Abstract: Biodiesel is widely investigated to solve the twin
problem of depletion of fossil fuel and environmental degradation.
The main objective of the present work is to compare performance,
emissions, and combustion characteristics of biodiesel derived from
cotton seed oil in a diesel engine with the baseline results of
petrodiesel fuel. Tests have been conducted on a single cylinder, four
stroke CIDI diesel engine with a speed of 1500 rpm and a fixed
compression ratio of 17.5 at different load conditions. The
performance parameters evaluated include brake thermal efficiency,
brake specific fuel consumption, brake power, indicated mean
effective pressure, mechanical efficiency, and exhaust gas
temperature. Regarding combustion study, cylinder pressure, rate of
pressure rise, net heat release rate, cumulative heat release, mean gas
temperature, mass fraction burned, and fuel line pressure were
evaluated. The emission parameters such as carbon monoxide, carbon
dioxide, un-burnt hydrocarbon, oxides of nitrogen, and smoke
opacity were also measured by a smoke meter and an exhaust gas
analyzer and compared with baseline results. The brake thermal
efficiency of cotton seed oil methyl ester (CSOME) was lower than
that of petrodiesel and brake specific fuel consumption was found to
be higher. However, biodiesel resulted in the reduction of carbon
dioxide, un-burnt hydrocarbon, and smoke opacity at the expense of
nitrogen oxides. Carbon monoxide emissions for biodiesel was higher
at maximum output power. It has been found that the combustion
characteristics of cotton seed oil methyl ester closely followed those
of standard petrodiesel. The experimental results suggested that
biodiesel derived from cotton seed oil could be used as a good
substitute to petrodiesel fuel in a conventional diesel without any
modification.
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: Green concrete are generally composed of recycling
materials as hundred or partial percent substitutes for aggregate,
cement, and admixture in concrete. To reduce greenhouse gas
emissions, efforts are needed to develop environmentally friendly
construction materials. Using of fly ash based geopolymer as an
alternative binder can help reduce CO2 emission of concrete. The
binder of geopolymer concrete is different from the ordinary Portland
cement concrete. Geopolymer Concrete specimens were prepared
with different concentration of NaOH solution M10, M14, and, M16
and cured at 60ºC in duration of 24 hours and 8 hours, in addition to
the curing in direct sunlight. Thus, it is necessary to study the effects
of the geopolymer binder on the behavior of concrete. Concrete is
made by using geopolymer technology is environmental friendly and
could be considered as part of the sustainable development. In this
study, the Local Alkaline Activator in Egypt and crashed stone as
coarse aggregate in fly ash based-geopolymer concrete was
investigated. This paper illustrates the development of mechanical
properties. Since the gained compressive strength for geopolymer
concrete at 28 days was in the range of 22.5MPa – 43.9MPa.
Abstract: Local steel slag is produced as a by-product during the
oxidation of steel pellets in an electric arc furnace. Using local steel
slag waste as a hundred substitutes of crashed stone in construction
materials would resolve the environmental problems caused by the
large-scale depletion of the natural sources of crashed stone. This
paper reports the experimental study to investigate the influence of a
hundred replacement of crashed stone as a coarse aggregate with
local steel slag, on the fresh and hardened geopolymer concrete
properties. The investigation includes traditional testing of hardening
concrete, for selected mixes of cement and geopolymer concrete. It
was found that local steel slag as a coarse aggregate enhanced the
slump test of the fresh state of cement and geopolymer concretes.
Nevertheless, the unit weight of concretes was affected. Meanwhile,
the good performance was observed when fly ash used as geopolymer
concrete based.
Abstract: Underwater acoustic networks have attracted great
attention in the last few years because of its numerous applications.
High data rate can be achieved by efficiently modeling the physical
layer in the network protocol stack. In Acoustic medium,
propagation speed of the acoustic waves is dependent on many
parameters such as temperature, salinity, density, and depth.
Acoustic propagation speed cannot be modeled using standard
empirical formulas such as Urick and Thorp descriptions. In this
paper, we have modeled the acoustic channel using real time data of
temperature, salinity, and speed of Bay of Bengal (Indian Coastal
Region). We have modeled the acoustic channel by using Mackenzie
speed equation and real time data obtained from National Institute of
Oceanography and Technology. It is found that acoustic propagation
speed varies between 1503 m/s to 1544 m/s as temperature and
depth differs. The simulation results show that temperature, salinity,
depth plays major role in acoustic propagation and data rate
increases with appropriate data sets substituted in the simulated
model.
Abstract: Steel slag is a by-product of the steel industry and can
be used potentially as aggregate in the asphalt mixture. This study
evaluates the use of Steel Slag Aggregates (SSA) as a substitute for
natural aggregates in the production of hot mix asphalt (HMA) for
road construction. Based on intensive laboratory testing program, the
characteristic properties of SSA were assessed to determine its
suitability to be used in HMA. Four different percentages (0, 50, 75,
and 100%) of SSA were used, and the proposed mix designs for
HMA were conducted in accordance with Marshall mix design. The
experiment results revealed that the addition of SSA has a significant
improvement on the properties of HMA. An increase in density and
stability and a reduction in flow and air voids values were clearly
observed in specimens prepared with 100% SSA. It is concluded that
the steel slag can be considered reasonable alternative source of
aggregate for concrete asphalt mixture production.
Abstract: In order to study the effect of different levels of triple
super phosphate chemical fertilizer and biological phosphate fertilizer
(fertile 2) on some morphological traits of corn this research was
carried out in Ahvaz in 2002 as a factorial experiment in randomized
complete block design with 4 replications). The experiment included
two factors: first, biological phosphate fertilizer (fertile 2) at three
levels of 0, 100, 200 g/ha; second, triple super phosphate chemical
fertilizer at three levels of 0, 60, 90 kg/ha of pure phosphorus (P2O5).
The obtained results indicated that fertilizer treatments had a
significant effect on some morphological traits at 1% probability
level. In this regard, P2B2 treatment (100 g/ha biological phosphate
fertilizer (fertile 2) and 60 kg/ha triple super phosphate fertilizer) had
the greatest plant height, stem diameter, number of leaves and ear
length. It seems that in Ahvaz weather conditions, decrease of
consumption of triple superphosphate chemical fertilizer to less than
a half along with the consumption of biological phosphate fertilizer
(fertile 2) is highly important in order to achieve optimal results.
Therefore, it can be concluded that biological fertilizers can be used
as a suitable substitute for some of the chemical fertilizers in
sustainable agricultural systems.
Abstract: Knowledge of bone mechanical properties is important
for bone substitutes design and fabrication, and more efficient
prostheses development. The aim of this study is to characterize the
viscoelastic behavior of bone specimens, through stress relaxation
and fatigue tests performed to trabecular bone samples from bovine
femoral heads. Relaxation tests consisted on preloading the samples
at five different magnitudes and evaluate them for 1020 seconds,
adjusting the results to a KWW mathematical model. Fatigue tests
consisted of 700 load cycles and analyze their status at the end of the
tests. As a conclusion we have that between relaxation stress and
each preload there is linear relation and for samples with initial
Young´s modulus greater than 1.5 GPa showed no effects due fatigue
test loading cycles.
Abstract: Mangosteen (Garcinia mangostana) pericarp is
considered as agricultural waste and not fully utilized in food
products. It is widely reported that mangosteen pericarp contains high
antioxidant properties. The objective of this study is to develop novel
yellow alkaline noodle (YAN) substituted with different levels of
mangosteen pericarp powder (MPP). YAN formulation was
substituted with different levels of MPP (0%, 5%, 10% and 15%).
The effect on nutritional and antioxidant properties was evaluated.
Higher substitution levels of MPP resulted in significant increase
(p
Abstract: There are several possibilities of reducing the required
amount of cement in concrete production. Natural zeolite is one of
the raw materials which can partly substitute Portland cement. The
effort to reduce the amount of Portland cement used in concrete
production is brings both economical as well as ecological benefits.
The paper presents the properties of concrete containing natural
zeolite as an active admixture in the concrete which partly substitutes
Portland cement. The properties discussed here bring information
about the basic mechanical properties and frost resistance of concrete
containing zeolite. The properties of concretes with the admixture of
zeolite are compared with a reference concrete with no content of
zeolite. The properties of the individual concretes are observed for
360 days.
Abstract: The biodegradable family of polymers
polyhydroxyalkanoates is an interesting substitute for convectional
fossil-based plastics. However, the manufacturing and environmental
impacts associated with their production via intracellular bacterial
fermentation are strongly dependent on the raw material used and on
energy consumption during the extraction process, limiting their
potential for commercialization. Industrial wastewater is studied in
this paper as a promising alternative feedstock for waste valorization.
Based on results from laboratory and pilot-scale experiments, a
conceptual process design, techno-economic analysis and life cycle
assessment are developed for the large-scale production of the most
common type of polyhydroxyalkanoate, polyhydroxbutyrate.
Intracellular polyhydroxybutyrate is obtained via fermentation of
microbial community present in industrial wastewater and the
downstream processing is based on chemical digestion with
surfactant and hypochlorite. The economic potential and
environmental performance results help identifying bottlenecks and
best opportunities to scale-up the process prior to industrial
implementation. The outcome of this research indicates that the
fermentation of wastewater towards PHB presents advantages
compared to traditional PHAs production from sugars because the
null environmental burdens and financial costs of the raw material in
the bioplastic production process. Nevertheless, process optimization
is still required to compete with the petrochemicals counterparts.
Abstract: This work reports the potential of using Palm Kernel
(PK) ash and shell as a partial substitute for Portland Cement (PC)
and coarse aggregate in the development of mortar and concrete. PK
ash and shell are agro-waste materials from palm oil mills, the
disposal of PK ash and shell is an environmental problem of concern.
The PK ash has pozzolanic properties that enables it as a partial
replacement for cement and also plays an important role in the
strength and durability of concrete, its use in concrete will alleviate
the increasing challenges of scarcity and high cost of cement. In order
to investigate the PC replacement potential of PK ash, three types of
PK ash were produced at varying temperature (350-750C) and they
were used to replace up to 50% PC. The PK shell was used to replace
up to 100% coarse aggregate in order to study its aggregate
replacement potential. The testing programme included material
characterisation, the determination of compressive strength, tensile
splitting strength and chemical durability in aggressive sulfatebearing
exposure conditions. The 90 day compressive results showed
a significant strength gain (up to 26.2 N/mm2). The Portland cement
and conventional coarse aggregate has significantly higher influence
in the strength gain compared to the equivalent PK ash and PK shell.
The chemical durability results demonstrated that after a prolonged
period of exposure, significant strength losses in all the concretes
were observed. This phenomenon is explained, due to lower change
in concrete morphology and inhibition of reaction species and the
final disruption of the aggregate cement paste matrix.
Abstract: In this paper, extract of papaya leaves are used as a
natural dye and combined by variations of solvent concentration
applied on DSSC (Dye-Sensitized Solar Cell). Indonesian geographic
located on the equator line occasions the magnitude of the potential
to develop organic solar cells made from extracts of chlorophyll as a
substitute for inorganic materials or synthetic dye on DSSC material.
Dye serves as absorbing photons which are then converted into
electrical energy. A conductive coated glass layer called TCO
(Transparent Conductive Oxide) is used as a substrate of electrode.
TiO2 nanoparticles as binding dye molecules, redox couple iodide/
tri-iodide as the electrolyte and carbon as the counter electrode in the
DSSC are used. TiO2 nanoparticles, organic dyes, electrolytes, and
counter electrode are arranged and combined with the layered
structure of the photo-catalyst absorption layer. Dye absorption
measurements using a spectrophotometer at 400-800 nm light
spectrum produces a total amount of chlorophyll 80.076 mg/l. The
test cell at 7 watt LED light with 5000 lux luminescence was
obtained Voc and Isc of 235.5 mV and 14 μA, respectively.
Abstract: E-learning has become an efficient and widespread
means of education at all levels of human activities. Statistics is no
exception. Unfortunately the main focus in statistics teaching is
usually paid to the substitution in formulas. Suitable websites can
simplify and automate calculations and provide more attention and
time to the basic principles of statistics, mathematization of real-life
situations and following interpretation of results. We now introduce
our own web-site for hypothesis testing. Its didactic aspects, the
technical possibilities of the individual tools, the experience of use
and the advantages or disadvantages are discussed in this paper. This
web-site is not a substitute for common statistical software but should
significantly improve the teaching of statistics at universities.
Abstract: Nanocrystalline powders of the lead-free piezoelectric
material, tantalum-substituted potassium sodium niobate
(K0.5Na0.5)(Nb0.9Ta0.1)O3 (KNNT), were produced using a Retsch
PM100 planetary ball mill by setting the milling time to 15h, 20h,
25h, 30h, 35h and 40h, at a fixed speed of 250rpm. The average
particle size of the milled powders was found to decrease from 12nm
to 3nm as the milling time increases from 15h to 25h, which is in
agreement with the existing theoretical model. An anomalous
increase to 98nm and then a drop to 3nm in the particle size were
observed as the milling time further increases to 30h and 40h
respectively. Various sizes of these starting KNNT powders were
used to investigate the effect of milling time on the microstructure,
dielectric properties, phase transitions and piezoelectric properties of
the resulting KNNT ceramics. The particle size of starting KNNT
was somewhat proportional to the grain size. As the milling time
increases from 15h to 25h, the resulting ceramics exhibit
enhancement in the values of relative density from 94.8% to 95.8%,
room temperature dielectric constant (εRT) from 878 to 1213, and
piezoelectric charge coefficient (d33) from 108pC/N to 128pC/N. For
this range of ceramic samples, grain size refinement suppresses the
maximum dielectric constant (εmax), shifts the Curie temperature (Tc)
to a lower temperature and the orthorhombic-tetragonal phase
transition (Tot) to a higher temperature. Further increase of milling
time from 25h to 40h produces a gradual degradation in the values of
relative density, εRT, and d33 of the resulting ceramics.
Abstract: Animal fats (camel, sheep, goat, rabbit and chicken)
and vegetable oils (corn, sunflower, palm oil and olive oil) were
substituted with different proportions (1, 5, 10 and 20%) of lard.
Fatty acid composition in TG and 2-MG were determined using
lipase hydrolysis and gas chromatography before and after
adulteration. Results indicated that, genuine lard had a high
proportion (60.97%) of the total palmitic acid at 2-MG. However, it
was 8.70%, 16.40%, 11.38%, 10.57%, 29.97 and 8.97% for camel,
beef, sheep, goat, rabbit and chicken, respectively. It could be noticed
also the position-2-MG is mostly occupied by unsaturated fatty acids
among all tested fats except lard. Vegetable oils (corn, sunflower,
palm oil and olive oil) revealed that the levels of palmitic acid
esterifies at 2-MG position was 6.84, 1.43, 9.86 and 1.70%,
respectively. It could be observed also the studied oils had a higher
level of unsaturated fatty acids in the same position, compared with
animal fats under investigation. Moreover, palmitic acid esterifies at
2-MG and PAEF increased gradually as the substituted levels
increased among all tested fat and oil samples. Statistical analysis
showed that the PAEF correlated well with lard level. The detection
of lard in some commercial processed foods (5 French fries, 4 Butter
fats, 5 processed meat and 6 candy samples) was carried out. Results
revealed that 2 samples of French fries and 4 samples of processed
meat contained lard due to their higher PAEF, while butter fat and
candy were free of lard.
Abstract: Esterification of p-bromo-m-cresol led to formation of
2-(4-bromo-3-methylphenoxy)acetate (1). 2-(4-Bromo-3-methyl
phenoxy)acetohydrazide (2) is derived from Compound (1) by
hydrazination. Compound (2) was reacted with different aromatic
aldehydes to yield N-(substituted benzylidiene)-2-(4-bromo-3-methyl
phenoxy)acetamide(3a-c). Cyclization of compound (3a-c) with
thioglycolic acid yielded 2-(4-bromo-3-methylphenoxy)-N-(4-oxo-2-
arylthiazolidin-3-yl) acetamide (4a-c). The newly synthesized
compounds were characterized on the basis of spectral studies and
evaluated for antibacterial and antifungal activities.
Abstract: Various biomass based resources, which can be used
as an extender, or a complete substitute of diesel fuel may have very
significant role in the development of agriculture, industrial and
transport sectors in the energy crisis. Use of Karanja oil methyl ester
biodiesel in a CI DI engine was found highly compatible with engine
performance along with lower exhaust emission as compared to
diesel fuel but with slightly higher NOx emission and low wear
characteristics. The combustion related properties of vegetable oils
are somewhat similar to diesel oil. Neat vegetable oils or their blends
with diesel, however, pose various long-term problems in
compression ignition engines. These undesirable features of
vegetable oils are because of their inherent properties like high
viscosity, low volatility, and polyunsaturated character. Pongamia
methyl ester (PME) was prepared by transesterification process using
methanol for long term engine operations. The physical and
combustion-related properties of the fuels thus developed were found
to be closer to that of the diesel. A neat biodiesel (PME) was selected
as a fuel for the tribological study of biofuels.
Two similar new engines were completely disassembled and
subjected to dimensioning of various vital moving parts and then
subjected to long-term endurance tests on neat biodiesel and diesel
respectively. After completion of the test, both the engines were
again disassembled for physical inspection and wear measurement of
various vital parts. The lubricating oil samples drawn from both
engines were subjected to atomic absorption spectroscopy (AAS) for
measurement of various wear metal traces present. The additional
lubricating property of biodiesel fuel due to higher viscosity as
compared to diesel fuel resulted in lower wear of moving parts and
thus improved the engine durability with a bio-diesel fuel. Results
reported from AAS tests confirmed substantially lower wear and thus
improved life for biodiesel operated engines.
Abstract: Depletion and hazardous gas emissions associated
with fossil fuels have caused scientists and global attention to focus
on the use of “alternative, eco-friendly substitutes for use in
Compression Ignition Engines. In this work, biodiesel was produced
by trans-esterification of soybean obtained from a Nigerian market
using Sodium Hydroxide (NaOH) as a catalyst.” After the
production, the physical properties (specific gravity to kinematic
viscosity and net calorific value) of the Soybean-biodiesel produced
and petrol diesel obtained from a filling station in Nigeria were
determined, and these properties conform to conventional standards
(ASTM). A cummins-6V-92TA DDEC diesel (Compression ignition,
CI) engine was run on various biodiesel-petrol diesel blends (0/100,
10/90, 20/80, 30/70 and 40/60), the B20 (blend 20/80) was found to
be the most satisfactory.
Abstract: In this study, fish bone waste was used as a new
catalyst for biodiesel production. Instead of discarding the fish bone
waste, it will be utilized as a source for catalyst that can provide
significant benefit to the environment. Also, it can be substitute as a
calcium oxide source instead of using eggshell, crab shell and snail
shell. The XRD and SEM analysis proved that calcined fish bone
contains calcium oxide, calcium phosphate and hydroxyapatite. The
catalyst was characterized using Scanning Electron Microscope
(SEM) and X-ray Diffraction (XRD).