Abstract: In the present work, forming limit diagrams and strain
distribution profile diagrams for extra deep drawing steel at room and
elevated temperatures have been determined experimentally by
conducting stretch forming experiments by using designed and
fabricated warm stretchforming tooling setup. With the help of
forming Limit Diagrams (FLDs) and strain, distribution profile
diagrams the formability of Extra Deep Drawing steel has been
analyzed and co-related with mechanical properties like strain
hardening COEFFICIENT (n) and normal anisotropy (r−). Mechanical
properties of EDD steel from room temperature to 4500C were
determined and discussed the impact of temperature on the properties
like work hardening exponent (n) anisotropy (r-) and strength
coefficient of the material. In addition, the fractured surfaces after
stretching have undergone the some metallurgical investigations and
attempt has been made to co-relate with the formability of EDD steel
sheets. They are co-related and good agreement with FLDs at various
temperatures.
Abstract: The aim of this paper is to introduce the notion of
intuitionistic fuzzy positive implicative ideals with thresholds (λ, μ) of
BCI-algebras and to investigate its properties and characterizations.
Abstract: In the present research, whole meal barley flour
(WBF) was supplemented with gelatinized corn flour (GCF) in 0 and
30%. Whole meal wheat flour (WWF) was mixed with defatted rice
bran (DRB) to produce 0, 20, 25, and 30% replacement levels.
Rheological properties of dough were studied. Thermal properties
and starch crystallinity of flours were evaluated. Flat bread, balady
bread and pie were prepared from the different flour blends. The
different bakeries were sensory evaluated. Color of raw materials and
crust of bakery products were determined. Nutrients contents of raw
flours and food products were assessed. Results showed that addition
of GCF to WBF increased the viscosity and falling number of the
produced dough. Water absorption, dough development time and
dough stability increased with increasing the level of DRB in dough
while, weakening and mixing tolerance index decreased.
Extensibility and energy decreased, while, resistance to extension
increased as DRB level increased. Gelatinized temperature of WWF,
WBF, GCF, and DRB were 13.26, 35.09, 28.33, and 39.63,
respectively. Starch crystallinity was affected when DRB was added
to WWF. The highest protein content was present in balady bread
made from 70% WWF and 30% DRB. The highest calcium,
phosphorus, and potassium levels were present in products made
from 100% WBF. Sensory attributes of the products were slightly
affected by adding DRB and GCF. Conclusion: Addition of DRB or
GCF to WWF or WBF, respectively affect the physical, chemical,
rheological and sensory properties of balady bread, flat bread, and pie
while improved their nutritive values.
Abstract: A Friction stir welding tool is a critical component to
the success of the process. The tool typically consists of a rotating
round shoulder and a threaded cylindrical pin that heats the work
piece, mostly by friction, and moves the softened alloy around it to
form the joint. In this research work, an attempt has been made to
investigate the relationship between FSW variables mainly tool
profile, rotating speed, welding speed and the mechanical properties
(tensile strength, yield strength, percentage elongation, and micro
hardness) of friction stir welded aluminum alloy 5083 joints. From
the experimental details, it can be assessed that the joint produced by
using Triflute profile tool has contribute superior mechanical and
structural properties as compared to Tapered unthreaded & Threaded
tool for 1000rpm.
Abstract: Fresh concrete has one of dynamic properties known
as slump. Slump of concrete is design to compatible with placing
method. Due to hydration reaction of cement, the slump of concrete
is loss through time. Therefore, delayed concrete probably get reject
because slump is unacceptable. In order to recover the slump of
delayed concrete the second dose of superplasticizer (naphthalene
based type F) is added into the system, the slump recovery can be
done as long as the concrete is not setting. By adding superplasticizer
as solution for recover unusable slump loss concrete may affects
other concrete properties. Therefore, this paper was observed setting
times and compressive strength of concrete after being re-dose with
chemical admixture type F (superplasticizer, naphthalene based) for
slump recovery. The concrete used in this study was fly ash concrete
with fly ash replacement of 0%, 30% and 50% respectively. Concrete
mix designed for test specimen was prepared with paste content (ratio
of volume of cement to volume of void in the aggregate) of 1.2 and
1.3, water-to-binder ratio (w/b) range of 0.3 to 0.58, initial dose of
superplasticizer (SP) range from 0.5 to 1.6%. The setting times of
concrete were tested both before and after re-dosed with different
amount of second dose and time of dosing. The research was
concluded that addition of second dose of superplasticizer would
increase both initial and final setting times accordingly to dosage of
addition. As for fly ash concrete, the prolongation effect was higher
as the replacement of fly ash increase. The prolongation effect can
reach up to maximum about 4 hours. In case of compressive strength,
the re-dosed concrete has strength fluctuation within acceptable range
of ±10%.
Abstract: This paper describes the development of new class of
epoxy based rice husk filled jute reinforced composites. Rice husk
flour is added in 0%, 1%, 3%, 5% by weight. Epoxy resin and
triethylenetetramine (T.E.T.A) is used as matrix and hardener
respectively. It investigates the mechanical properties of the
composites and a comparison is done for monolithic jute composite
and the filled ones. The specimens are prepared according to the
ASTM standards and experimentation is carried out using INSTRON
8801. The result shows that with the increase of filler percentage the
tensile properties increases but compressive and flexural properties
decreases.
Abstract: Cadmium oxide (CdO) nanoparticles have been
prepared by chemical coprecipitation method. The synthesized
nanoparticles were characterized by X-ray diffraction analysis
(XRD), scanning electron microscopy (SEM), transmission electron
microscopy (TEM), UV analysis, and dielectric studies. The
crystalline nature and particle size of the CdO nanoparticles were
characterized by Powder X-ray diffraction analysis (XRD). The
morphology of prepared CdO nanoparticles was studied by scanning
electron microscopy. The particle size was studied using the
transmission electron microscopy (TEM).The optical properties were
obtained from UV-Vis absorption spectrum. The dielectric properties
of CdO nanoparticles were studied in the frequency range of 50 Hz–5
MHz at different temperatures. The frequency dependence of the
dielectric constant and dielectric loss is found to decrease with an
increase in the frequency at different temperatures. The ac
conductivity of CdO nanoparticle has been studied.
Abstract: The strain intensity and redundant strains, dependent
in multistage TRIP wire drawing processes from values used single
partial reductions, should influence on the intensity of transformation
the retained austenite into martensite and thereby on mechanical
properties of drawn wires. The numerical analysis of drawing
processes with use of Drawing 2D programme, for steel wires made
from TRIP steel with 0,29% has been shown in the work. The change
of strain intensity εc and the values of redundant strain εxy, has been
determined for particular draws in dependence of used single partial
reductions.
Abstract: Value addition to agricultural produce is of possible
potential in reducing poverty, improving food security and
malnutrition, therefore the need to develop small and microenterprises
of sweet potato production. A study was carried out in Nigeria to determine the acceptability
of blends sweet potato (Ipomea batatas) and commodities yellow
maize (Zea mays), millet (Pennisetum glaucum), soybean (Glycine
max), bambara groundnut (Vigna subterranean), guinea corn
(Sorghum vulgare), wheat (Triticum aestivum), and roselle (Hibiscus
sabdariffa) through sensory evaluation. Sweet potato (Ipomea batatas) roots were processed using two
methods: oven and sun drying. The blends were also assessed in
terms of functional, chemical and color properties. Most acceptable blends include BAW (80:20 of sweet
potato/wheat), BBC (80:20 of sweet potato/guinea corn), AAB (60:40
of sweet potato/guinea corn), YTE (100% soybean), TYG (100%
sweet potato), KTN (100% wheat flour), XGP (80:20 of sweet
potato/soybean), XAX (60:40 of sweet potato/wheat), LSS (100%
Roselle), CHK (100% Guinea corn), and ABC (60:40% of sweet
potato/ yellow maize). In addition, carried out chemical analysis
revealed that sweet potato has high percentage of vitamins A and C,
potassium (K), manganese (Mn), calcium (Ca), magnesium (Mg) and
iron (Fe) and fibre content. There is also an increase of vitamin A and
Iron in the blended products.
Abstract: Carbon dioxide is one of the major greenhouse gas
(GHG) contributors. It is an obligation of the industry to reduce the
amount of carbon dioxide emission to the acceptable limits.
Tremendous research and studies are reported in the past and still the
quest to find the suitable and economical solution of this problem
needed to be explored in order to develop the most plausible absorber
for carbon dioxide removal. Amino acids can be potential alternate
solvents for carbon dioxide capture from gaseous streams. This is due
to its ability to resist oxidative degradation, low volatility and its
ionic structure. In addition, the introduction of promoter-like
piperazine to amino acid helps to further enhance the solubility. In
this work, the effect of piperazine on thermo physical properties and
solubility of β-Alanine aqueous solutions were studied for various
concentrations. The measured physicochemical properties data was
correlated as a function of temperature using least-squares method
and the correlation parameters are reported together with it respective
standard deviations. The effect of activator piperazine on the CO2
loading performance of selected amino acid under high-pressure
conditions (1bar to 10bar) at temperature range of (30 to 60)oC was
also studied. Solubility of CO2 decreases with increasing temperature
and increases with increasing pressure. Quadratic representation of
solubility using Response Surface Methodology (RSM) shows that
the most important parameter to optimize solubility is system
pressure. The addition of promoter increases the solubility effect of
the solvent.
Abstract: Bezier curves have useful properties for path
generation problem, for instance, it can generate the reference
trajectory for vehicles to satisfy the path constraints. Both algorithms
join cubic Bezier curve segment smoothly to generate the path. Some
of the useful properties of Bezier are curvature. In mathematics,
curvature is the amount by which a geometric object deviates from
being flat, or straight in the case of a line. Another extrinsic example
of curvature is a circle, where the curvature is equal to the reciprocal
of its radius at any point on the circle. The smaller the radius, the
higher the curvature thus the vehicle needs to bend sharply. In this
study, we use Bezier curve to fit highway-like curve. We use
different approach to find the best approximation for the curve so that
it will resembles highway-like curve. We compute curvature value by
analytical differentiation of the Bezier Curve. We will then compute
the maximum speed for driving using the curvature information
obtained. Our research works on some assumptions; first, the Bezier
curve estimates the real shape of the curve which can be verified
visually. Even though, fitting process of Bezier curve does not
interpolate exactly on the curve of interest, we believe that the
estimation of speed are acceptable. We verified our result with the
manual calculation of the curvature from the map.
Abstract: This paper presents numerical analysis in terms of
buckling resistance of GFRP sandwich infill panels system under the
influence of increased temperature on the foam core. Failure mode
under in-plane compression is studied by means of numerical analysis
with ABAQUS platform. Parameters considered in this study are
contact length and both the type of foam for core and the variation of
its module elastic under the thermal influence. Increment of
temperature is considered in static cases and only applied to core.
Indeed, it is proven that the effect of temperature alters the mechanical
properties of the entire panel system. Moreover, the rises of
temperature result in a decrease in strength of the panel. This is due to
the polymeric nature of this material. Additionally, the contact length
also displays the effect on performance of infill panel. Their
significance factors are based on type of polymer for core. Therefore,
by comparing difference type of core material, the variation can be
reducing.
Abstract: Inspired by the Formula-1 competition, IMechE
(Institute of Mechanical Engineers) and Formula SAE (Society of
Mechanical Engineers) organize annual competitions for University
and College students worldwide to compete with a single-seat racecar
they have designed and built. Design of the chassis or the frame is a
key component of the competition because the weight and stiffness
properties are directly related with the performance of the car and the
safety of the driver. In addition, a reduced weight of the chassis has
direct influence on the design of other components in the car. Among
others, it improves the power to weight ratio and the aerodynamic
performance. As the power output of the engine or the battery
installed in the car is limited to 80 kW, increasing the power to
weight ratio demands reduction of the weight of the chassis, which
represents the major part of the weight of the car. In order to reduce
the weight of the car, ION Racing team from University of
Stavanger, Norway, opted for a monocoque design. To ensure
fulfilment of the competition requirements of the chassis, the
monocoque design should provide sufficient torsional stiffness and
absorb the impact energy in case of possible collision. The study reported in this article is based on the requirements for
Formula Student competition. As part of this study, diverse
mechanical tests were conducted to determine the mechanical
properties and performances of the monocoque design. Upon a
comprehensive theoretical study of the mechanical properties of
sandwich composite materials and the requirements of monocoque
design in the competition rules, diverse tests were conducted
including 3-point bending test, perimeter shear test and test for
absorbed energy. The test panels were homemade and prepared with
equivalent size of the side impact zone of the monocoque, i.e. 275
mm x 500 mm, so that the obtained results from the tests can be
representative. Different layups of the test panels with identical core
material and the same number of layers of carbon fibre were tested
and compared. Influence of the core material thickness was also
studied. Furthermore, analytical calculations and numerical analysis
were conducted to check compliance to the stated rules for Structural
Equivalency with steel grade SAE/AISI 1010. The test results were
also compared with calculated results with respect to bending and
torsional stiffness, energy absorption, buckling, etc. The obtained results demonstrate that the material composition
and strength of the composite material selected for the monocoque
design has equivalent structural properties as a welded frame and thus
comply with the competition requirements. The developed analytical
calculation algorithms and relations will be useful for future
monocoque designs with different lay-ups and compositions.
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: This paper aimed to introduce the solution of concrete
slump recovery using chemical admixture type-F (superplasticizer,
naphthalene base) to the practice in order to solve unusable concrete
problem due to concrete loss its slump, especially for those tropical
countries that have faster slump loss rate. In the other hand, randomly
adding superplasticizer into concrete can cause concrete to segregate.
Therefore, this paper also develops the estimation model used to
calculate amount of second dose of superplasticizer need for concrete
slump recovery. Fresh properties of ordinary Portland cement
concrete with volumetric ratio of paste to void between aggregate
(paste content) of 1.1-1.3 with water-cement ratio zone of 0.30 to
0.67 and initial superplasticizer (naphthalene base) of 0.25%-1.6%
were tested for initial slump and slump loss for every 30 minutes for
one and half hour by slump cone test. Those concretes with slump
loss range from 10% to 90% were re-dosed and successfully
recovered back to its initial slump. Slump after re-dosed was tested
by slump cone test. From the result, it has been concluded that, slump
loss was slower for those mix with high initial dose of
superplasticizer due to addition of superplasticizer will disturb
cement hydration. The required second dose of superplasticizer was
affected by two major parameters, which were water-cement ratio
and paste content, where lower water-cement ratio and paste content
cause an increase in require second dose of superplasticizer. The
amount of second dose of superplasticizer is higher as the solid
content within the system is increase, solid can be either from cement
particles or aggregate. The data was analyzed to form an equation use
to estimate the amount of second dosage requirement of
superplasticizer to recovery slump to its original.
Abstract: The main purpose of this study is to assess the
sediment quality and potential ecological risk in marine sediments in
Gymea Bay located in south Sydney, Australia. A total of 32 surface
sediment samples were collected from the bay. Current track
trajectories and velocities have also been measured in the bay. The
resultant trace elements were compared with the adverse biological
effect values Effect Range Low (ERL) and Effect Range Median
(ERM) classifications. The results indicate that the average values of
chromium, arsenic, copper, zinc, and lead in surface sediments all
reveal low pollution levels and are below ERL and ERM values. The
highest concentrations of trace elements were found close to
discharge points and in the inner bay, and were linked with high
percentages of clay minerals, pyrite and organic matter, which can
play a significant role in trapping and accumulating these elements.
The lowest concentrations of trace elements were found to be on the
shoreline of the bay, which contained high percentages of sand
fractions. It is postulated that the fine particles and trace elements are
disturbed by currents and tides, then transported and deposited in
deeper areas. The current track velocities recorded in Gymea Bay had
the capability to transport fine particles and trace element pollution
within the bay. As a result, hydrodynamic measurements were able to
provide useful information and to help explain the distribution of
sedimentary particles and geochemical properties. This may lead to
knowledge transfer to other bay systems, including those in remote
areas. These activities can be conducted at a low cost, and are
therefore also transferrable to developing countries. The advent of
portable instruments to measure trace elements in the field has also
contributed to the development of these lower cost and easily applied
methodologies available for use in remote locations and low-cost
economies.
Abstract: Large quantities of solid wastes being generated
worldwide from sources such as household, domestic, industrial,
commercial and construction demolition activities, leads to
environmental concerns. Utilization of these wastes in making
building construction materials can reduce the magnitude of the
associated problems. When these waste products are used in place of
other conventional materials, natural resources and energy are
preserved and expensive and/or potentially harmful waste disposal is
avoided. Recycling which is regarded as the third most preferred waste
disposal option, with its numerous environmental benefits, stand as a
viable option to offset the environmental impact associated with the
construction industry. This paper reviews the results of laboratory tests and important
research findings, and the potential of using these wastes in building
construction materials with focus on sustainable development.
Research gaps, which includes; the need to develop standard mix
design for solid waste based building materials; the need to develop
energy efficient method of processing solid waste use in concrete; the
need to study the actual behavior or performance of such building
materials in practical application and the limited real life application
of such building materials have also been identified. A research is being proposed to develop an environmentally
friendly, lightweight building block from recycled waste paper,
without the use of cement, and with properties suitable for use as
walling unit. This proposed research intends to incorporate,
laboratory experimentation and modeling to address the identified
research gaps.
Abstract: Geopolymer composites reinforced with flax fabrics
and nanoclay are fabricated and studied for physical and mechanical
properties using X-Ray Diffraction (XRD), Fourier Transform
Infrared Spectroscopy (FTIR), and Scanning Electron Microscope
(SEM). Nanoclay platelets at a weight of 1.0%, 2.0%, and 3.0% were
added to geopolymer pastes. Nanoclay at 2.0 wt.% was found to
improve density and decrease porosity while improving flexural
strength and post-peak toughness. A microstructural analysis
indicated that nanoclay behaves as filler and as an activator
supporting geopolymeric reaction while producing a higher content
geopolymer gel improving the microstructure of binders. The process
enhances adhesion between the geopolymer matrix and flax fibres.
Abstract: In this study, the effects and interactions of reaction
time and capping agent assistance during sol-gel synthesis of
magnesium substituted hydroxyapatite nanopowder (MgHA) on
hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P
ratio and mean crystallite size was examined experimentally as well
as through statistical analysis. MgHA nanopowders were synthesized
by sol-gel technique at room temperature using aqueous solution of
calcium nitrate tetrahydrate, magnesium nitrate hexahydrate and
potassium dihydrogen phosphate as starting materials. The reaction
time for sol-gel synthesis was varied between 15 to 60 minutes. Two
process routes were followed with and without addition of
triethanolamine (TEA) in the solutions. The elemental compositions
of as-synthesized powders were determined using X-ray fluorescence
(XRF) spectroscopy. The functional groups present in the assynthesized
MgHA nanopowders were established through Fourier
Transform Infrared Spectroscopy (FTIR). The amounts of phases
present, Ca/P ratio and mean crystallite sizes of MgHA nanopowders
were determined using X-ray diffraction (XRD). The HA content in
biphasic mixture of HA and β-TCP and Ca/P ratio in as-synthesized
MgHA nanopowders increased effectively with reaction time of sols
(p0.15, two way ANOVA). The MgHA nanopowders
synthesized with TEA assistance exhibited 14 nm lower crystallite
size (p
Abstract: This paper presents the results of a study on the
influence of varying percentages of rock bridges along a basal surface
defining a biplanar failure mode. A pseudo-coupled-hydromechanical
brittle fracture analysis is adopted using the state-of-the-art code
Slope Model. Model results show that rock bridge failure is strongly
influenced by the incorporation of groundwater pressures. The
models show that groundwater pressure can promote total failure of a
5% rock bridge along the basal surface. Once the percentage of the
rock bridges increases to 10 and 15%, although, the rock bridges are
broken, full interconnection of the surface defining the basal surface
of the biplanar mode does not occur. Increased damage is caused
when the rock bridge is located at the daylighting end of the basal
surface in proximity to the blast damage zone. As expected, some
cracking damage is experienced in the blast damage zone, where
properties representing a good quality controlled damage blast
technique were assumed. Model results indicate the potential increase
of permeability towards the blast damage zone.