Abstract: Journal bearings used in IC engines are prone to premature
failures and are likely to fail earlier than the rated life due to
highly impulsive and unstable operating conditions and frequent
starts/stops. Vibration signature extraction and wear debris analysis
techniques are prevalent in industry for condition monitoring of
rotary machinery. However, both techniques involve a great deal of
technical expertise, time, and cost. Limited literature is available on
the application of these techniques for fault detection in reciprocating
machinery, due to the complex nature of impact forces that
confounds the extraction of fault signals for vibration-based analysis
and wear prediction. In present study, a simulation model was developed to investigate
the bearing wear behaviour, resulting because of different operating
conditions, to complement the vibration analysis. In current
simulation, the dynamics of the engine was established first, based on
which the hydrodynamic journal bearing forces were evaluated by
numerical solution of the Reynold’s equation. In addition, the
essential outputs of interest in this study, critical to determine wear
rates are the tangential velocity and oil film thickness between the
journals and bearing sleeve, which if not maintained appropriately,
have a detrimental effect on the bearing performance. Archard’s wear prediction model was used in the simulation to
calculate the wear rate of bearings with specific location information
as all determinative parameters were obtained with reference to crank
rotation. Oil film thickness obtained from the model was used as a
criterion to determine if the lubrication is sufficient to prevent contact
between the journal and bearing thus causing accelerated wear. A
limiting value of 1 μm was used as the minimum oil film thickness
needed to prevent contact. The increased wear rate with growing
severity of operating conditions is analogous and comparable to the
rise in amplitude of the squared envelope of the referenced vibration
signals. Thus on one hand, the developed model demonstrated its
capability to explain wear behaviour and on the other hand it also
helps to establish a co-relation between wear based and vibration
based analysis. Therefore, the model provides a cost effective and
quick approach to predict the impending wear in IC engine bearings
under various operating conditions.
Abstract: The statistical study has become indispensable for various fields of knowledge. Not any different, in Geotechnics the study of probabilistic and statistical methods has gained power considering its use in characterizing the uncertainties inherent in soil properties. One of the situations where engineers are constantly faced is the definition of a probability distribution that represents significantly the sampled data. To be able to discard bad distributions, goodness-of-fit tests are necessary. In this paper, three non-parametric goodness-of-fit tests are applied to a data set computationally generated to test the goodness-of-fit of them to a series of known distributions. It is shown that the use of normal distribution does not always provide satisfactory results regarding physical and behavioral representation of the modeled parameters.
Abstract: The major environmental risk of soil pollution is the
contamination of groundwater by infiltration of organic and inorganic
pollutants which can cause a serious menace. To prevent this risk and
to protect the groundwater, we proceeded in this study to test the
reliability of a biosolid as barrier to prevent the migration of very
dangerous pollutants as ‘Cadmium’ through the different soil layers. In this study, we tried to highlight the effect of several parameters
such as: turbidity (different cycle of Hydration/Dehydration),
rainfall, effect of initial Cd(II) concentration and the type of soil.
These parameters allow us to find the most effective manner to
integrate this barrier in the soil. From the results obtained, we found a
significant effect of the barrier. Indeed, the recorded passing
quantities are lowest for the highest rainfall; we noted also that the
barrier has a better affinity towards higher concentrations; the most
retained amounts of cadmium has been in the top layer of the two
types of soil tested, while the lowest amounts of cadmium are
recorded in the bottom layers of soils.
Abstract: A myriad of environmental issues face the Nigerian
industrial region, resulting from; oil and gas production, mining,
manufacturing and domestic wastes. Amidst these, much effort has
been directed by stakeholders in the Nigerian oil producing regions,
because of the impacts of the region on the wider Nigerian economy.
Although collaborative environmental management has been noted as
an effective approach in managing environmental issues, little
attention has been given to the roles and practices of stakeholders in
effecting a collaborative environmental management framework for
the Nigerian oil-producing region. This paper produces a framework
to expand and deepen knowledge relating to stakeholders aspects of
collaborative roles in managing environmental issues in the Nigeria
oil-producing region. The knowledge is derived from analysis of
stakeholders’ practices – studied through multiple case studies using
document analysis. Selected documents of key stakeholders –
Nigerian government agencies, multi-national oil companies and host
communities, were analyzed. Open and selective coding was
employed manually during document analysis of data collected from
the offices and websites of the stakeholders. The findings showed
that the stakeholders have a range of roles, practices, interests, drivers
and barriers regarding their collaborative roles in managing
environmental issues. While they have interests for efficient resource
use, compliance to standards, sharing of responsibilities, generating
of new solutions, and shared objectives; there is evidence of major
barriers and these include resource allocation, disjointed policy,
ineffective monitoring, diverse socio- economic interests, lack of
stakeholders’ commitment and limited knowledge sharing. However,
host communities hold deep concerns over the collaborative roles of
stakeholders for economic interests, particularly, where government
agencies and multi-national oil companies are involved. With these
barriers and concerns, a genuine stakeholders’ collaboration is found
to be limited, and as a result, optimal environmental management
practices and policies have not been successfully implemented in the
Nigeria oil-producing region. A framework is produced that describes
practices that characterize collaborative environmental management
might be employed to satisfy the stakeholders’ interests. The
framework recommends critical factors, based on the findings, which
may guide a collaborative environmental management in the oil
producing regions. The recommendations are designed to re-define
the practices of stakeholders in managing environmental issues in the
oil producing regions, not as something wholly new, but as an
approach essential for implementing a sustainable environmental
policy. This research outcome may clarify areas for future research as
well as to contribute to industry guidance in the area of collaborative
environmental management.
Abstract: In the present study, feasibility of the selective surface
hydrophilization of polyvinyl chloride (PVC) by microwave treatment
was evaluated to facilitate the separation from automotive shredder
residue (ASR), by the froth flotation. The combination of 60 sec
microwave treatment with PAC, a sharp and significant decrease about
16.5° contact angle of PVC was observed in ASR plastic compared
with other plastics. The microwave treatment with the addition of PAC
resulted in a synergetic effect for the froth flotation, which may be a
result of the 90% selective separation of PVC from ASR plastics, with
82% purity. While, simple mixing with a nanometallic Ca/CaO/PO4
dispersion mixture immobilized 95-100% of heavy metals in ASR
soil/residues. The quantity of heavy metals leached from thermal
residues after treatment by nanometallic Ca/CaO/PO4 was lower than
the Korean standard regulatory limit for hazardous waste landfills.
Microwave treatment can be a simple and effective method for PVC
separation from ASR plastics.
Abstract: Strong anthropogenic impact has uncontrolled
consequences on the nature of the soil. Hence, up-to-date sustainable
methods of soil state improvement are essential. Investigators provide
the evidence that biochar can positively effects physical, chemical,
and biological soil properties and the abundance of mycorrhizal fungi
which are in the focus of this study. The main aim of the present
investigation is to demonstrate the effect of two types of plant growth
promoting bacteria (PGPB) inoculums along with the beech wood
biochar and mineral N additives on mycorrhizal colonization.
Experiment has been set up in laboratory conditions with containers
filled with arable soil from the protection zone of the main water
source “Brezova nad Svitavou”. Lactuca sativa (lettuce) has been
selected as a model plant. Based on the obtained data, it can be
concluded that mycorrhizal colonization increased as the result of
combined influence of biochar and PGPB inoculums amendment. In
addition, correlation analyses showed that the numbers of main
groups of cultivated bacteria were dependent on the degree of
mycorrhizal colonization.
Abstract: Coal fly ash, an industrial by product of coal
combustion thermal power plants is considered as a hazardous
material and its improper disposal has become an environmental
issue. On the other hand, manufacturing conventional clay bricks
involves on consumption of large amount of clay and leads
substantial depletion of topsoil. This paper unveils the possibility of
using fly ash as a partial replacement of clay for brick manufacturing
considering the local technology practiced in Bangladesh. The effect
of fly ash with different replacing ratio (0%, 20%, 30%, 40%, and
50% by volume) of clay on properties of bricks was studied. Bricks
were made in the field parallel to ordinary bricks marked with
specific number for different percentage to identify them at time of
testing. No physical distortion is observed in fly ash brick after
burning in the kiln. Results from laboratory test show that
compressive strength of brick is decreased with the increase of fly
ash and maximum compressive strength is found to be 19.6 MPa at
20% of fly ash. In addition, water absorption of fly ash brick is
increased with the increase of fly ash. The abrasion value and
Specific gravity of coarse aggregate prepared from brick with fly ash
also studied and the results of this study suggests that 20% fly ash
can be considered as the optimum fly ash content for producing good
quality bricks utilizing present practiced technology.
Abstract: Biochar can be produced from the waste matter and its
application has been associated with returning of carbon in large
amounts into the soil. The impacts of this material on physical and
chemical properties of soil have been described. The biggest part of
the research work is dedicated to the hypothesis of this material’s
toxic effects on the soil life regarding its effect on the soil biological
component. At present, it has been worked on methods which could
eliminate these undesirable properties of biochar. One of the
possibilities is to mix biochar with organic material, such as compost,
or focusing on the natural processes acceleration in the soil. In the
experiment has been used as the addition of compost as well as the
elimination of toxic substances by promoting microbial activity in
aerated water environment. Biochar was aerated for 7 days in a
container with a volume of 20 l. This way modified biochar had six
times higher biomass production and reduce mineral nitrogen
leaching. Better results have been achieved by mixing biochar with
compost.
Abstract: Production fluids are transported from the platform to
tankers or process facilities through transfer pipelines. Water being
one of the heavier phases tends to settle at the bottom of pipelines
especially at low flow velocities and this has adverse consequences
for pipeline integrity. On restart after a shutdown, this could result in
corrosion and issues for process equipment, thus the need to have the
heavier liquid dispersed into the flowing lighter fluid. This study
looked at the flow regime of low water cut and low flow velocity oil
and water flow using conductive film thickness probes in a large
diameter 4-inch pipe to obtain oil and water interface height and the
interface structural velocity. A wide range of 0.1–1.0 m/s oil and
water mixture velocities was investigated for 0.5–5% water cut. Two
fluid model predictions were used to compare with the experimental
results.
Abstract: Selenium is an-antioxidant which is important for
human health enters food chain through crops. In Kenya Zea mays is
consumed by 96% of population hence is a cheap and convenient
method to provide selenium to large number of population. Several
soil factors are known to have antagonistic effects on selenium
speciation hence the uptake by Zea mays. There are no studies in
Kenya that has been done to determine the effects of soil
characteristics (pH, Tcarbon, CEC, Eh) affect accumulation of
selenium in Zea mays grains in Maize Belt in Kenya. About 100 Zea mays grain samples together with 100 soil samples
were collected from the study site put in separate labeled Ziplocs and
were transported to laboratories at room temperature for analysis.
Maize grains were analyzed for selenium while soil samples were
analyzed for pH, Cat Ion Exchange Capacity, total carbon, and
electrical conductivity. The mean selenium in Zea mays grains varied from 1.82 ± 0.76
mg/Kg to 11±0.86 mg/Kg. There was no significant difference
between selenium levels between different grain batches {χ (Df =76)
= 26.04 P= 1.00} The pH levels varied from 5.43± 0.58 to 5.85±
0.32. No significant correlations between selenium in grains and soil
pH (Pearson’s correlations = - 0.143), and between selenium levels in
grains and the four (pH, Tcarbon, CEC, Eh) soil chemical
characteristics {F (4,91) = 0.721 p = 0.579} was observed. It can be concluded that the soil chemical characteristics in the
study site did not significantly affect the accumulation of native
selenium in Zea mays grains.
Abstract: The aim of this study is to evaluate the effect of
supplementing broiler starter diet with different levels of an essential
oil blend (EOB) containing capsaicin, carvacrol and cinnamaldehyde
on the performance of broilers. A total of 300 day-old straight-run
Cobb broiler chicks were randomly assigned to three treatments after
7-day group brooding following a completely randomized design
(CRD). Birds assigned in treatment 1 were given starter basal diet
while those in treatments 2 and 3 were given starter basal diet with
400 mg/kg antibiotic growth promoter (AGP) and 150 mg/kg EOB,
respectively, until the 28th day. Basal finisher feed were given for all
the treatments until harvest. Following 37 d feeding, body weight
gain, feed consumption, feed efficiency, dressing percentage,
livability and jejunal villi height were determined. Results showed no
significant differences (P>0.05) in growth performance. However,
villi height and crypt depth was significantly lower for birds fed
EOB.
Abstract: A number of studies have been conducted recently to
investigate the influence of randomly oriented fibers on some
engineering properties of cohesive and cohesionless soils. However,
few studies have been carried out on freezing-thawing behavior of
fine-grained soils modified with discrete fiber inclusions and additive
materials. This experimental study was performed to investigate the
effect of randomly distributed polypropylene fibers (PP) and some
additive materials [e.g.., borogypsum (BG), fly ash (FA) and cement
(C)] on freezing-thawing durability (mass losses) of a fine-grained
soil for 6, 12, and 18 cycles. The Taguchi method was applied to the
experiments and a standard L9 orthogonal array (OA) with four
factors and three levels were chosen. A series of freezing-thawing
tests were conducted on each specimen. 0-20% BG, 0-20% FA, 0-
0.25% PP and 0-3% of C by total dry weight of mixture were used in
the preparation of specimens. Experimental results showed that the
most effective materials for the freezing-thawing durability (mass
losses) of the samples were borogypsum and fly ash. The values of
mass losses for 6, 12 and 18 cycles in optimum conditions were
16.1%, 5.1% and 3.6%, respectively.
Abstract: Geological and tectonic framework indicates that
Bangladesh is one of the most seismically active regions in the world.
The Bengal Basin is at the junction of three major interacting plates:
the Indian, Eurasian, and Burma Plates. Besides there are many
active faults within the region, e.g. the large Dauki fault in the north.
The country has experienced a number of destructive earthquakes due
to the movement of these active faults. Current seismic provisions of
Bangladesh are mostly based on earthquake data prior to the 1990.
Given the record of earthquakes post 1990, there is a need to revisit
the design provisions of the code. This paper compares the base shear
demand of three major cities in Bangladesh: Dhaka (the capital city),
Sylhet, and Chittagong for earthquake scenarios of magnitudes
7.0MW, 7.5MW, 8.0MW, and 8.5MW using a stochastic model. In
particular, the stochastic model allows the flexibility to input region
specific parameters such as shear wave velocity profile (that were
developed from Global Crustal Model CRUST2.0) and include the
effects of attenuation as individual components. Effects of soil
amplification were analysed using the Extended Component
Attenuation Model (ECAM). Results show that the estimated base
shear demand is higher in comparison with code provisions leading to
the suggestion of additional seismic design consideration in the study
regions.
Abstract: The understanding of geotechnical characteristics of
near-surface material and the effects of the groundwater is very
important problem in such as site studies. For showing the relations
between seismic data and groundwater, we selected about 25 km2 as
the study area. It has been presented which is a detailed work of
seismic data and groundwater depths of Gokpinar Damp area.
Seismic waves velocity (Vp and Vs) are very important parameters
showing the soil properties. The seismic records were used the
method of the multichannel analysis of surface waves near area of
Gokpinar Damp area. Sixty sites in this area have been investigated
with survey lines about 60 m in length. MASW (Multichannel
analysis of surface wave) method has been used to generate onedimensional
shear wave velocity profile at locations. These shear
wave velocities are used to estimate equivalent shear wave velocity in
the study area at every 2 and 5 m intervals up to a depth of 45 m.
Levels of equivalent shear wave velocity of soil are used the
classified of the study area. After the results of the study, it must be
considered as components of urban planning and building design of
Gokpinar Damp area, Denizli and the application and use of these
results should be required and enforced by municipal authorities.
Abstract: Strong anthropogenic impact has uncontrolled
consequences on the nature of the soil. Hence, up-to-date sustainable
methods of soil state improvement are essential. Investigators provide
the evidence that biochar can positively effects physical, chemical,
and biological soil properties and the abundance of mycorrhizal fungi
which are in the focus of this study. The main aim of the present
investigation is to demonstrate the effect of two types of plant growth
promoting bacteria (PGPB) inoculums along with the beech wood
biochar and mineral N additives on mycorrhizal colonization.
Experiment has been set up in laboratory conditions with containers
filled with arable soil from the protection zone of the main water
source “Brezova nad Svitavou”. Lactuca sativa (lettuce) has been
selected as a model plant. Based on the obtained data, it can be
concluded that mycorrhizal colonization increased as the result of
combined influence of biochar and PGPB inoculums amendment. In
addition, correlation analyses showed that the numbers of main
groups of cultivated bacteria were dependent on the degree of
mycorrhizal colonization.
Abstract: To maintain a healthy balanced loyalty, whether to art
or society, posits a debatable issue. The artist is always on the look
out for the potential tension between those two realms. Therefore,
one of the most painful dilemmas the artist finds is how to function in
a society without sacrificing the aesthetic values of his/her work. In
other words, the life-long awareness of failure which derives from the
concept of the artist as caught between unflattering social realities
and the need to invent genuine art forms becomes a fertilizing soil for
the artists to be tackled. Thus, within the framework of this dilemma,
the question of the responsibility of the artist and the relationship of
the art to politics will be illuminating. To a larger extent, however, in
drama, this dilemma is represented by the fictional characters of the
play. The present paper tackles the idea of the amorality of the artist in
selected plays by Tom Stoppard. However, Stoppard’s awareness of
his situation as a refugee has led him to keep at a distance from
politics. He tried hard to avoid any intervention into the realms of
political debate, especially in his earliest work. On the one hand, it is
not meant that he did not interest in politics as such, but rather he
preferred to question it than to create a fixed ideological position. On
the other hand, Stoppard’s refusal to intervene in politics is ascribed
to his feeling of gratitude to Britain where he settled. As a result,
Stoppard has frequently been criticized for a lack of political
engagement and also for not leaning too much for the left when he
does engage. His reaction to these public criticisms finds expression
in his self-conscious statements which defensively stressed the
artifice of his work. He, like Oscar Wilde thinks that the
responsibility of the artist is devoted to the realm of his/her art.
Consequently, his consciousness for the role of the artist is truly
reflected in his two plays, Artist Descending a Staircase (1972) and
Travesties (1974).
Abstract: In the vicinity of red sea about 15 fungi species were
isolated from oil contaminated sites. On the basis of aptitude to
degrade the crude oil and DCPIP assay, two fungal isolates were
selected amongst 15 oil degrading strains. Analysis of ITS-1, ITS-2
and amplicon pyrosequencing studies of fungal diversity revealed
that these strains belong to Penicillium and Aspergillus species. Two
strains that proved to be the most efficient in degrading crude oil was
Aspergillus niger (54%) and Penicillium commune (48%) Subsequent
to two weeks of cultivation in BHS medium the degradation rate
were recorded by using spectrophotometer and GC-MS. Hence, it is
cleared that these fungal strains has capability of degradation and can
be utilize for cleaning the Saudi Arabian environment.
Abstract: The post-rain puddles problem that occurs in the first
yard of Prambanan Temple are often disturbing visitor activity. A
poodle layer and a drainage system had ever built to avoid such a
problem, but puddles still did not stop appearing after rain.
Permeability parameter needs to be determined by using a simpler
procedure to find exact method of solution. The instrument modelling
was proposed according to the development of field permeability
testing instrument. This experiment used a proposed Constant
Discharge method. Constant Discharge method used a tube poured
with constant water flow from unsaturated until saturated soil
condition. Volumetric water content (θ) were monitored by soil
moisture measurement device. The results were correlations between
k and θ which were drawn by numerical approach from Van
Genutchen model. Parameters θr optimum value obtained from the
test was at very dry soil. Coefficient of permeability with a density of
19.8 kN/m3 for unsaturated conditions was in range of 3 x 10-6
cm/sec (Sr=68%) until 9.98 x 10-4 cm/sec (Sr=82%). The equipment
and testing procedure developed in this research was quite effective,
simple and easy to be implemented on determining field soil
permeability coefficient value of sandy soil. Using constant discharge
method in proposed permeability test, value of permeability
coefficient under unsaturated condition can be obtained without
establish soil water characteristic curve.
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: 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.