Abstract: The chemical and physical characteristics of rainwater
harvested from a typical rooftop were progressively studied. The
samples of rainwater collected were analyzed for pH, major ion
concentrations, TDS, turbidity, conductivity. All the Physicochemical
constituents fell within the WHO guideline limits at some points as
rainfall progresses except the pH. All the components of rainwater
quality measured during the study showed higher concentrations
during the early stages of rainfall and reduce as time progresses.
There was a downward trend in terms of pH as rain progressed, with
18% of the samples recording pH below the WHO limit of 6.5-8.0. It
was observed that iron concentration was above the WHO threshold
value of 0.3 mg/l on occasions of heavy rains. The results revealed
that most of physicochemical characteristics of rainwater samples
were generally below the WHO threshold, as such, the rainwater
characteristics showed satisfactory conditions in terms of
physicochemical constituents.
Abstract: An important problem for the CaSO4/CaSO4･1/2H2O
Chemical heat pump (CHP) is that the material is deactivated through
repetitive reaction between hydration and dehydration in which the
crystal phase of the material is transformed from III-CaSO4 to
II-CaSO4. We investigated suppression on the phase change by adding
a sulfated compound. The most effective material was MgSO4. MgSO4
doping increased the durability of CaSO4 in the actual CHP repetitive
cycle of hydration/dehydration to 3.6 times that of undoped CaSO4.
The MgSO4-doped CaSO4 showed a higher phase transition
temperature and activation energy for crystal transformation from
III-CaSO4 to II-CaSO4. MgSO4 doping decreased the crystal lattice
size of CaSO4･1/2H2O and II-CaSO4 to smaller than that of undoped
CaSO4. Modification of the crystal structure is considered to be related
to the durability change in CaSO4 resulting from MgSO4 doping.
Abstract: Sol-enhanced Zn-Ni-Al2O3 nanocomposite coatings
were electroplated on mild steel by our newly developed solenhanced
electroplating method. In this method, transparent Al2O3 sol
was added into the acidic Zn-Ni bath to produced Zn-Ni-Al2O3nanocomposite
coatings. The chemical composition, microstructure and
mechanical properties of the composite and alloy coatings deposited
at two different agitation speed were investigated. The structure of all
coatings was single γ-Ni5Zn21 phase. The composite coatings possess
refined crystals with higher microhardness compared to Zn-Ni alloy
coatings. The wear resistance of Zn-Ni coatings was improved
significantly by incorporation of alumina nano particles into the
coatings. Higher agitation speed provided more uniform coatings
with smaller grain sized and slightly higher microhardness.
Considering composite coatings, high agitation speeds may facilitate
co-deposition of alumina in the coatings.
Abstract: Chitosan functionalized Fe3O4-Au core shell
nanoparticles have been prepared using a two-step wet chemical
approach using NaBH4 as reducing agent for formation of Au in
ethylene glycol. X-ray diffraction studies shows individual phases of
Fe3O4 and Au in the as prepared samples with crystallite size of 5.9
and 11.4 nm respectively. The functionalization of the core-shell
nanostructure with Chitosan has been confirmed using Fourier
transform infrared spectroscopy along with signatures of octahedral
and tetrahedral sites of Fe3O4 below 600cm-1. Mössbauer
spectroscopy shows decrease in particle-particle interaction in
presence of Au shell (72% sextet) than pure oleic coated Fe3O4
nanoparticles (88% sextet) at room temperature. At 80K, oleic acid
coated Fe3O4 shows only sextets whereas the Chitosan functionalized
Fe3O4 and Chitosan functionalized Fe3O4@Au core shell show
presence of 5 and 11% doublet, respectively.
Abstract: Advanced treatments such as forward osmosis (FO)
can be used to separate or reject nutrients from secondary treated
effluents. Forward osmosis uses the chemical potential across the
membrane, which is the osmotic pressure gradient, to induce water to
flow through the membrane from a feed solution (FS) into a draw
solution (DS). The performance of FO is affected by the membrane
characteristics, composition of the FS and DS, and operating
conditions. The aim of this study was to investigate the optimum
velocity and temperature for nutrient rejection and water flux
performance in FO treatments. MgCl2 was used as the DS in the FO
process. The results showed that higher cross flow velocities yielded
higher water fluxes. High rejection of nutrients was achieved by using
a moderate cross flow velocity at 0.25 m/s. Nutrient rejection was
insensitive to temperature variation, whereas water flux was
significantly impacted by it. A temperature of 25°C was found to be
good for nutrient rejection.
Abstract: The concentrations of heavy metals in sediments of
Qua Iboe River Estuary (QIRE) were monitored at four different
sampling locations in wet and dry seasons. A preliminary survey to
determine the four sampling stations along the river continuum
showed that the area spanned between
Abstract: The article presents a plasma chemical technology for
processing solid fuels, using examples of bituminous and brown
coals. Thermodynamic and experimental investigation of the
technology was made. The technology allows producing synthesis
gas from the coal organic mass and valuable components (technical
silicon, ferrosilicon, aluminum, and carbon silicon, as well as
microelements of rare metals, such as uranium, molybdenum,
vanadium, etc.) from the mineral mass. The thusly produced highcalorific
synthesis gas can be used for synthesis of methanol, as a
high-calorific reducing gas instead of blast-furnace coke as well as
power gas for thermal power plants.
Abstract: A field study was conducted to evaluate the efficacy of
safflower plant for phytoremediation of contaminated soils. The
experiment was performed on an agricultural fields contaminated by
the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. Field
experiments with randomized complete block design with five
treatments (control, compost amendments added at 20 and 40 t/daa,
and vermicompost amendments added at 20 and 40 t/daa) were
carried out. The quality of safflower seeds and oil (heavy metals and
fatty acid composition) were determined. Tested organic amendments
significantly influenced the chemical composition of safflower seeds
and oil. The compost and vermicompost treatments significantly
reduced heavy metals concentration in safflower seeds and oils, but
the effect differed among them. Addition of vermicompost and
compost leads to an increase in the content of palmitic acid and
linoleic acid, and a decrease in the stearic and oleic acids compared
with the control. A significant increase in the quantity of saturated
acids was observed in the variants with 20 t/daa of compost and 20
t/daa of vermicompost (9.1 and 8.9% relative to the control).
Safflower is a plant which is tolerant to heavy metals and can be
successfully used in the phytoremediation of heavy metal
contaminated soils. The processing of seeds to oil and using the
obtained oil for nutritional purposes will greatly reduce the cost of
phytoremediation.
Abstract: The atmospheres in many cities along the coastal lines
in the world have been rapidly changed to coastal-industrial
atmosphere. Hence, it is vital to investigate the corrosion behavior of
steel exposed to this kind of environment. In this present study,
Electrochemical Impedance Spectrography (EIS) and film thickness
measurement were applied to monitor the corrosion behavior of
weathering steel covered with a thin layer of the electrolyte in a
wet-dry cyclic condition, simulating a coastal-industrial environment
at 25oC and 60% RH. The results indicate that in all cycles, the
corrosion rate increases during the drying process due to an increase in
anion concentration and an acceleration of oxygen diffusion enhanced
by the effect of the thinning out of the electrolyte. During the wet-dry
cyclic corrosion test, the long-term corrosion behavior of this steel
depends on the periods of exposure. Corrosion process is first
accelerated and then decelerated. The decelerating corrosion process is
contributed to the formation of the protective rust, favored by the
wet-dry cycle and the acid regeneration process during the rusting
process.
Abstract: Hypersonic flows around spatial vehicles during their reentry phase in planetary atmospheres are characterized by intense aerothermodynamics phenomena. The aim of this work is to analyze high temperature flows around an axisymmetric blunt body taking into account chemical and vibrational non-equilibrium for air mixture species and the no slip condition at the wall. For this purpose, the Navier-Stokes equations system is resolved by the finite volume methodology to determine the flow parameters around the axisymmetric blunt body especially at the stagnation point and in the boundary layer along the wall of the blunt body. The code allows the capture of shock wave before a blunt body placed in hypersonic free stream. The numerical technique uses the Flux Vector Splitting method of Van Leer. CFL coefficient and mesh size level are selected to ensure the numerical convergence.
Abstract: The potential neuroprotective effect of Phyllantus
nuriri against Fe2+ and sodium nitroprusside (SNP) induced oxidative
stress in mitochondria of rats brain was evaluated. Cellular viability
was assessed by MTT reduction, reactive oxygen species (ROS)
generation was measured using the probe 2,7-dichlorofluoresce
indiacetate (DCFH-DA). Glutathione content was measured using
dithionitrobenzoic acid (DTNB). Fe2+ (10μM) and SNP (5μM)
significantly decreased mitochondrial activity, assessed by MTT
reduction assay, in a dose-dependent manner, this occurred in parallel
with increased glutathione oxidation, ROS production and lipid
peroxidation end-products (thiobarbituric acid reactive substances,
TBARS). The co-incubation with methanolic extract of Phyllantus
nuriri (10-200 μg/ml) reduced the disruption of mitochondrial
activity, gluthathione oxidation, ROS production as well as the
increase in TBARS levels caused by both Fe2+ and SNP in a dose
dependent manner. HPLC analysis of the extract revealed the
presence of gallic acid (20.540.01), caffeic acid (7.930.02), rutin
(25.310.05), quercetin (31.280.03) and kaemferol (14.360.01).
This result suggests that these phytochemicals account for the
protective actions of P. niruri against Fe2+ and SNP -induced
oxidative stress. Our results show that P. nuriri consist important
bioactive molecules in the search for an improved therapy against the
deleterious effects of Fe2+, an intrinsic producer of reactive oxygen
species (ROS), that leads to neuronal oxidative stress and
neurodegeneration.
Abstract: Egg yolk oil is a natural source of bioactive
compounds such as unsaturated fatty acids, oil soluble vitamins,
pigments and others. Bioactive compound content in egg yolk oil
depends from its content in eggs, from which oil was extracted. Many
studies show that bioactive compound content in egg is correlated to
the content of these compounds in hen feed, but there is also an
opinion that hen housing systems also have influence on egg
chemical content. The aim of this study was to determine which
factor, laying hen housing system or hen diet, has a primary influence
on bioactive compound content in egg yolk oil. The egg yolk oil was
extracted from eggs obtained from 4 different hen housing systems:
cage, barn and two groups of free range. All hens were fed with
commercially produced compound feed except one group of free
range hens which get free diet – pastured hens. Extracted egg yolk
oils were analyzed for fatty acids, oil soluble vitamins and β-carotene
content. α-tocopherol, ergocalcipherol and polyunsaturated fatty acid
content in egg yolk oil was higher from eggs obtained from all
housing systems where hens were fed with commercial compound
feed. β-carotene and retinol content in egg yolk oils from free range
free diet eggs was significantly (p>0.05) higher that from other eggs
because hens have access to green forage. Hen physical activity in
free range housing systems decreases content of some bioactive
compound in egg yolk oil.
Abstract: Ulexite (Na2O.2CaO.5B2O3.16H2O) is boron mineral
that is found in large quantities in the Turkey and world. In this
study, the dissolution of this mineral in the disodium hydrogen
phosphate solutions has been studied. Temperature, concentration,
stirring speed, solid liquid ratio and particle size were selected as
parameters. The experimental results were successfully correlated by
linear regression using Statistica program. Dissolution curves were
evaluated shrinking core models for solid-fluid systems. It was
observed that increase in the reaction temperature and decrease in the
solid/liquid ratio causes an increase the dissolution rate of ulexite.
The activation energy was found to be 63.4 kJ/mol. The leaching of
ulexite was controlled by chemical reaction.
Abstract: In the present work, Electrochemical Impedance
Spectrocopy (EIS) is applied to study the transport of different metal
cations through a cation-exchange membrane. This technique enables
the identification of the ionic-transport characteristics and to
distinguish between different transport mechanisms occurring at
different current density ranges. The impedance spectra are
dependent on the applied dc current density, on the type of cation and
on the concentration.
When the applied dc current density increases, the diameter of the
impedance spectra loops increases because all the components of
membrane system resistance increase. The diameter of the impedance
plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the
increased interactions between the negatively charged sulfonic
groups of the membrane and the cations with greater charge. Nyquist
plots are shifted towards lower values of the real impedance, and its
diameter decreases with the increase of concentration due to the
decrease of the solution resistance.
Abstract: A central element of higher education today is the
“core” or “general education” curriculum: that configuration of
courses that often encompasses the essence of liberal arts education.
Ensuring that such offerings reflect the mission and values of the
institution is a challenge faced by most college and universities, often
more than once. This paper presents an action model of program
planning designed to structure the processes of developing,
implementing and revising core curricula in a manner consistent with
key institutional goals and objectives. Through presentation of a case
study from a university in the United States, the elements of needs
assessment, stakeholder investment and collaborative compromise
are shown as key components of a planning strategy that can produce
a general education program that is comprehensive, academically
rigorous, assessable, and mission consistent. The paper concludes
with recommendations for both the implementation and evaluation of
such programs in practice.
Abstract: Coal fly ash is formed as a solid waste product from
the combustion of coal in coal fired power stations. Huge amounts of
fly ash are produced globally every year and are predicted to
increase. Nowadays, less than half of the fly ash is used as a raw
material for cement manufacturing, construction and the rest of it is
disposed as a waste causing yet another environmental concern. For
this reason, the recycling of this kind of slurries into useful materials
is quite important in terms of economical and environmental aspects.
The purpose of this study is to evaluate the Orhaneli and
Tuncbilek coal fly ashes for utilization in some industrial
applications. Therefore the mineralogical and chemical compositions
of these fly ashes were analyzed by X-ray fluorescence spectroscopy,
ourier-transform infrared spectrometer, and X-ray diffraction. The
silicon (Si) and aluminum (Al) in the fly ashes were activated by
alkali fusion technique with sodium hydroxide. The obtained extracts
were analyzed for Si and Al content by inductively coupled plasma
optical emission spectrometry.
Abstract: This study was carried out to investigate the adverse
effect of industrial wastewater on surface water quality in Gebeng
industrial estate, Pahang, Malaysia. Surface water was collected from
six sampling stations. Physicochemical parameters were
characterized based on in-situ and ex-situ analysis according to
standard methods by American Public Health Association (APHA).
Selected heavy metals were determined by using Inductively Coupled
Plasma Mass Spectrometry (ICP MS). The results revealed that the
concentration of heavy metals such as Pb, Cu, Cd, Cr and Hg were
high in samples. The results also showed that the value of Pb and Hg
were higher in the wet season in comparison to dry season.
According to Malaysia National Water Quality Standard (NWQS)
and Water Quality Index (WQI) all the sampling station were
categorized as class IV (highly polluted). The present study revealed
that the adverse effects of careless disposal of wastes and directly
discharge of effluents affected on surface water quality. Therefore,
the authorities should implement the laws to ensure the proper
practices of wastewater management for environmental sustainability
around the study area.
Abstract: Chrome tannery wastewater causes serious environmental hazard due to its high pollution potential. As a result, rigorous treatment is necessary for abatement of pollution from this type of wastewater. There are many research studies on chrome tannery wastewater treatment in the field of physical, chemical, and biological methods. In general, biological treatment process is found ineffective for direct application because of adverse effects by toxic chromium, sulphide, chloride etc. However, biological methods were employed mainly for a few sub processes generating significant amount of organic matter and without chromium, chlorides etc. In this context the present paper reviews the characteristics feature and pollution potential of wastewater generated from chrome tannery units and treatment of the same. The different biological processes used earlier and their chronological development for treatment of the chrome tannery wastewater are thoroughly reviewed in this paper. In this regard, the scope of hybrid bioreactor - an advanced technology option has also been explored, as this kind of treatment is well suited for the wastewater having inhibitory substances.
Abstract: In this paper static scheme of under-frequency based load shedding is considered for chemical and petrochemical industries with islanded distribution networks relying heavily on the primary commodity to ensure minimum production loss, plant downtime or critical equipment shutdown. A simplistic methodology is proposed for in-house implementation of this scheme using underfrequency relays and a step by step guide is provided including the techniques to calculate maximum percentage overloads, frequency decay rates, time based frequency response and frequency based time response of the system. Case study of FFL electrical system is utilized, presenting the actual system parameters and employed load shedding settings following the similar series of steps. The arbitrary settings are then verified for worst overload conditions (loss of a generation source in this case) and comprehensive system response is then investigated.
Abstract: Lignocellolusic material is a substance that is resistant to be degraded by microorganisms or hydrolysis enzymes. To be used as materials for biofuel production, it needs pretreatment process to improve efficiency of hydrolysis. In this work, chemical pretreatments on rice straw using three diluted organic acids, including acetic acid, citric acid, oxalic acid, were optimized. Using Response Surface Methodology (RSM), the effect of three pretreatment parameters, acid concentration, treatment time, and reaction temperature, on pretreatment efficiency were statistically evaluated. The results indicated that dilute oxalic acid pretreatment led to the highest enhancement of enzymatic saccharification by commercial cellulase and yielded sugar up to 10.67 mg/ml when using 5.04% oxalic acid at 137.11 oC for 30.01 min. Compared to other acid pretreatment by acetic acid, citric acid, and hydrochloric acid, the maximum sugar yields are 7.07, 6.30, and 8.53 mg/ml, respectively. Here, it was demonstrated that organic acids can be used for pretreatment of lignocellulosic materials to enhance of hydrolysis process, which could be integrated to other applications for various biorefinery processes.