Abstract: This work studies the effect of chemical composition
on the activity and selectivity of γ–alumina supported CuO/
MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether
(DME) and methanol. The catalysts were prepared by impregnation
of the support with an aqueous solution of copper nitrate, manganese
nitrate and CrO3 under different conditions. Thermal, XRD and TPR
analysis were performed. The catalytic measurements of single
compounds oxidation were carried out on continuous flow equipment
with a four-channel isothermal stainless steel reactor. Flow-line
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions that mimic closely the industrial
ones was used. The reactant and product gases were analyzed by
means of on-line gas chromatographs.
On the basis of XRD analysis it can be concluded that the active
component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at
least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4,
Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio.
Chemical composition strongly influences catalytic properties, this
influence being quite variable with regards to the different processes.
The rate of CO oxidation rapidly decrease with increasing of
chromium content in the active component while for the DME was
observed the reverse trend. It was concluded that the best
compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and
Mn/Cr molar ratio from 1:3 to 1:4.
Abstract: Mustard leaves are rich in folates, vitamin A, K and
B-complex. Mustard greens are low in calories and fats and rich in
dietary fiber. They are rich in potassium, manganese, iron, copper,
calcium, magnesium and low in sodium. It is very rich in antioxidants
and Phytonutrients. For the optimization of process variables
(moisture content and mustard leave powder), the experiments were
conducted according to central composite Face Centered Composite
design of RSM. The mustard leaves powder was replaced with
composite flour (a combination of rice, chickpea and corn in the ratio
of 70:15:15). The extrudate was extruded in a twin screw extruder at
a barrel temperature of 120°C. The independent variables were
mustard leaves powder (2-10 %) and moisture content (12-20 %).
Responses analyzed were bulk density, water solubility index, water
absorption index, lateral expansion, antioxidant activity, total
phenolic content, and overall acceptability. The optimum conditions
obtained were 7.19 g mustard leaves powder in 100g premix having
16.8% moisture content (w.b).
Abstract: For this study, a town based soil database created in
Gümüsçay District of Biga Town, Çanakkale, Turkey. Crop and
livestock production are major activities in the district. Nutrient
management is mainly based on commercial fertilizer application
ignoring the livestock manure. Within the boundaries of district, 122
soil sampling points determined over the satellite image. Soil samples
collected from the determined points with the help of handheld
Global Positioning System. Labeled samples were sent to a
commercial laboratory to determine 11 soil parameters including
salinity, pH, lime, organic matter, nitrogen, phosphorus, potassium,
iron, manganese, copper and zinc. Based on the test results soil maps
for mentioned parameters were developed using remote sensing, GIS,
and geostatistical analysis. In this study we developed a GIS database
that will be used for soil nutrient management. Methods were
explained and soil maps and their interpretations were summarized in
the study.
Abstract: The development of active and stable catalysts
without noble metals for low temperature oxidation of exhaust gases
remains a significant challenge. The purpose of this study is to
determine the influence of the preparation method on the catalytic
activity of the supported copper-manganese mixed oxides in terms of
VOCs oxidation. The catalysts were prepared by impregnation of γ-
Al2O3 with copper and manganese nitrates and acetates and the
possibilities for CO, CH3OH and dimethyl ether (DME) oxidation
were evaluated using continuous flow equipment with a four-channel
isothermal stainless steel reactor. Effect of the support, Cu/Mn mole
ratio, heat treatment of the precursor and active component loading
were investigated. Highly active alumina supported Cu-Mn catalysts
for CO and VOCs oxidation were synthesized. The effect of
preparation conditions on the activity behavior of the catalysts was
discussed.
The synergetic interaction between copper and manganese species
increases the activity for complete oxidation over mixed catalysts.
Type of support, calcination temperature and active component
loading along with catalyst composition are important factors,
determining catalytic activity. Cu/Mn molar ratio of 1:5, heat
treatment at 450oC and 20 % active component loading are the best
compromise for production of active catalyst for simultaneous
combustion of CO, CH3OH and DME.
Abstract: Interaction of Schiff base complexes of Iron and
Manganese: Iron [N, N’ Bis (5- (triphenyl phosphonium methyl)
salicylidene) -1, 2 ethanediamine) chloride, [Fe Salen]Cl; Manganese
[N, N’ Bis (5- (triphenyl phosphonium methyl) salicylidene) -1, 2
ethanediamine) acetate, were investigated by spectroscopic and
isothermal titration calorimetry techniques (ITC).
The absorbance spectra of complexes have shown hyper and
hypochromism in the presence of DNA that is indication of
interaction of complexes with DNA. The linear dichroism (LD)
measurements confirmed the bending of DNA in the presence of
complexes.
Furthermore, Isothermal titration calorimetry experiments
approved that complexes bound to DNA on the base of both
electrostatic and hydrophobic interactions. More, ITC profile exhibits
the existence of two binding phases for the complexes. Antibacterial
activity of ligand and complexes were tested in vitro to evaluate their
activity against the gram positive and negative bacteria.
Abstract: Microbial fuel cells (MFCs) represent a promising
technology for simultaneous bioelectricity generation and wastewater
treatment. Catalysts are significant portions of the cost of microbial
fuel cell cathodes. Many materials have been tested as aqueous
cathodes, but air-cathodes are needed to avoid energy demands for
water aeration. The sluggish oxygen reduction reaction (ORR) rate at
air cathode necessitates efficient electrocatalyst such as carbon
supported platinum catalyst (Pt/C) which is very costly. Manganese
oxide (MnO2) was a representative metal oxide which has been
studied as a promising alternative electrocatalyst for ORR and has
been tested in air-cathode MFCs. However the single MnO2 has poor
electric conductivity and low stability. In the present work, the MnO2
catalyst has been modified by doping Pt nanoparticle. The goal of the
work was to improve the performance of the MFC with minimum Pt
loading. MnO2 and Pt nanoparticles were prepared by hydrothermal
and sol gel methods, respectively. Wet impregnation method was
used to synthesize Pt/MnO2 catalyst. The catalysts were further used
as cathode catalysts in air-cathode cubic MFCs, in which anaerobic
sludge was inoculated as biocatalysts and palm oil mill effluent
(POME) was used as the substrate in the anode chamber. The asprepared
Pt/MnO2 was characterized comprehensively through field
emission scanning electron microscope (FESEM), X-Ray diffraction
(XRD), X-ray photoelectron spectroscopy (XPS), and cyclic
voltammetry (CV) where its surface morphology, crystallinity,
oxidation state and electrochemical activity were examined,
respectively. XPS revealed Mn (IV) oxidation state and Pt (0)
nanoparticle metal, indicating the presence of MnO2 and Pt.
Morphology of Pt/MnO2 observed from FESEM shows that the
doping of Pt did not cause change in needle-like shape of MnO2
which provides large contacting surface area. The electrochemical
active area of the Pt/MnO2 catalysts has been increased from 276 to
617 m2/g with the increase in Pt loading from 0.2 to 0.8 wt%. The
CV results in O2 saturated neutral Na2SO4 solution showed that
MnO2 and Pt/MnO2 catalysts could catalyze ORR with different
catalytic activities. MFC with Pt/MnO2 (0.4 wt% Pt) as air cathode
catalyst generates a maximum power density of 165 mW/m3, which
is higher than that of MFC with MnO2 catalyst (95 mW/m3). The
open circuit voltage (OCV) of the MFC operated with MnO2 cathode
gradually decreased during 14 days of operation, whereas the MFC
with Pt/MnO2 cathode remained almost constant throughout the
operation suggesting the higher stability of the Pt/MnO2 catalyst.
Therefore, Pt/MnO2 with 0.4 wt% Pt successfully demonstrated as an
efficient and low cost electrocatalyst for ORR in air cathode MFC with higher electrochemical activity, stability and hence enhanced
performance.
Abstract: In this paper, snow samples containing dust particles
from several sampling points around the city of Ostrava were
analyzed. The pH values of sampled snow were measured and solid
particles analyzed. Particle size, zeta potential and content of selected
heavy metals were determined in solid particles. The pH values of
most samples lay in the slightly acid region. Mean values of particle
size ranged from 290.5 to 620.5 nm. Zeta potential values varied
between -5 and -26.5 mV. The following heavy metal concentration
ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g,
manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest
values of copper and lead were found in the vicinity of busy
crossroads, and on the contrary, the highest levels of manganese and
iron were detected close to a large steelworks. The proportion
between pH values, zeta potentials, particle sizes and heavy metal
contents was established. Zeta potential decreased with rising pH
values and, simultaneously, heavy metal content in solid particles
increased. At the same time, higher metal content corresponded to
lower particle size.
Abstract: This study was conducted to evaluate the manganese
removal from aqueous solution using Banana peels activated carbon
(BPAC). Batch experiments have been carried out to determine the
influence of parameters such as pH, biosorbent dose, initial metal ion
concentrations and contact times on the biosorption process. From
these investigations, a significant increase in percentage removal of
manganese 97.4% is observed at pH value 5.0, biosorbent dose 0.8 g,
initial concentration 20 ppm, temperature 25 ± 2°C, stirring rate 200
rpm and contact time 2h. The equilibrium concentration and the
adsorption capacity at equilibrium of the experimental results were
fitted to the Langmuir and Freundlich isotherm models; the Langmuir
isotherm was found to well represent the measured adsorption data
implying BPAC had heterogeneous surface. A raw groundwater
samples were collected from Baharmos groundwater treatment plant
network at Embaba and Manshiet Elkanater City/District-Giza,
Egypt, for treatment at the best conditions that reached at first phase
by BPAC. The treatment with BPAC could reduce iron and
manganese value of raw groundwater by 91.4% and 97.1%,
respectively and the effect of the treatment process on the
microbiological properties of groundwater sample showed decrease
of total bacterial count either at 22°C or at 37°C to 85.7% and 82.4%,
respectively. Also, BPAC was characterized using SEM and FTIR
spectroscopy.
Abstract: Amyloid aggregation of polypeptides is related to a
growing number of pathologic states known as amyloid disorders. In
recent years, blocking or reversing amyloid aggregation via the use of
small compounds are considered as two useful approaches in
hampering the development of these diseases. In this research, we
have compared the ability of several manganese-salen derivatives, as
synthetic compounds, and apigenin, as a natural flavonoid, to inhibit
of hen egg-white lysozyme (HEWL) aggregation, as an in vitro
model system.
Different spectroscopic analyses such as Thioflavin T (ThT) and
Anilinonaphthalene-8-sulfonic acid (ANS) fluorescence, Congo red
(CR) absorbance along with transmission electron microscopy were
used in this work to monitor the HEWL aggregation kinetic and
inhibition. Our results demonstrated that both type of compounds
were capable to prevent the formation of lysozyme amyloid
aggregation in vitro. In addition, our data indicated that synthetic
compounds had higher activity to inhibit of the β-sheet structures
relative to natural compound. Regarding the higher antioxidant
activities of the salen derivatives, it can be concluded that in addition
to aromatic rings of each of the compounds, the potent antioxidant
properties of salen derivatives contributes to lower lysozyme fibril
accumulation.
Abstract: Nowadays harmonization of sanitary and hygienic standards of environmental quality with international standards is crucial part of integration of Russia into the international community. Harmonization of Russian and international ambient air quality standards may be realized by risk-based standards development. In this paper approaches to risk-based standards development and examples of these approaches implementation are presented.
Abstract: The health and environmental risk of eating mushrooms grown in Abakaliki were evaluated in terms of heavy metals accumulation. Mushroom samples were collected from four different farms located at Izzi, Amajim, Amana and Amudo and analyzed for (iron, lead, manganese and cadmium) using Bulk Scientific Atomic Absorption Spectrophotometer 205. Results indicates mean range of concentrations of the trace metals in the mushrooms were Fe (0.22-152. 03), Mn (0.74-9.76), Pb (0.01.0.80), Cd (0.61-0.82) mg/L respectively. Accumulation of Cd on the four locations under investigation was higher than the UK Government Food Science Surveillance and World Health Organization maximum recommended levels in mushroom for human consumption. The Fe and Mn contaminants of Amudo were significant and show the impact of anthropogenic/atmospheric pollution. The potential sources of the heavy metals in the mushrooms were from urban waste, dust from mining and quarrying activities, natural geochemistry of the area, and use of inorganic fertilizers
Abstract: The aim of this research paper was based on an examination of sources of water supply and water quality for local consumption, conducted at eco- tourism villages of Suan Luang Sub- District Municipality of Amphawa District, Samut Songkram Province. The study incorporated both questionnaire and field work of water testing as the research tool and method. The sample size of 288 households was based on the population of the district, whereas the selected sample water sources were from 60 households: 30 samples were ground water and another 30 were surface water. Degree of heavy metal contamination in the water including copper, iron, manganese, zinc, cadmium and lead was investigated utilizing the Atomic Absorption- Direct Aspiration method. The findings unveiled that 96.0 percent of household water consumption was based on water supply, while the rest on canal, river and rain water. The household behavior of consumption revealed that 47.2 percent of people routinely consumed water without boiling or filtering prior to consumption. The investigation of water supply quality found that the degree of heavy metal contamination including metal, lead, iron, copper, manganese and cadmium met the standards of the Department of Health.
Abstract: This study aimed to evaluated the surface water quality for agriculture and consumption in the Amphawa District. The surface water quality parameters in this study included water temperature, turbidity, conductivity, salinity, pH, dissolved oxygen, BOD, nitrate, suspended solids, phosphorus, total dissolved solids (TDS), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), lead (Pb) and cadmium (Cd). The water samples were collected from small excavation, Lychee, Pomelo and Coconut orchards for 3 seasons from January to December 2011.
The surface water quality from small excavation, Lychee, pomelo and coconut orchards were met the type III of surface water quality standard. The concentration of heavy metal and did not differ significantly at 0.05 level, except dissolved oxygen.
The surface water was suitable for consumption by the usual sterile and generally improving water quality through the process before and was suitable for agriculture.
Abstract: Combustion of fuels in industrial and transport sector has lead to an alarming release of polluting gases to the atmosphere. Carbon monoxide is one such pollutant, which is formed as a result of incomplete oxidation of the fuel. In order to analyze the effect of catalyst on the reduction of CO emissions to the atmosphere, two catalysts Mn2O3 and Hopcalite are considered. A model was formed based on mass and energy balance equations. Results show that Hopcalite catalyst as compared to Mn2O3 catalyst helped in faster conversion of the polluting gas as the operating temperature of the hopcalite catalyst is much lower as compared to the operating temperature of Mn2O3 catalyst.
Abstract: Impurity metals such as manganese and cadmium
from high-tenor cobalt electrolyte solution were selectively removed
by solvent extraction method using Co-D2EHPA after converting the functional group of D2EHPA with Co2+ ions. The process parameters
such as pH, organic concentration, O/A ratio, kinetics etc. were
investigated and the experiments were conducted by batch tests in the laboratory bench scale. Results showed that a significant amount
of manganese and cadmium can be extracted using Co-D2EHPA for the optimum processing of cobalt electrolyte solution at equilibrium pH about 3.5. The McCabe-Thiele diagram, constructed from the
extraction studies showed that 100% impurities can be extracted through four stages for manganese and three stages for cadmium
using O/A ratio of 0.65 and 1.0, respectively. From the stripping study, it was found that 100% manganese and cadmium can be stripped from the loaded organic using 0.4 M H2SO4 in a single
contact. The loading capacity of Co-D2EHPA by manganese and cadmium were also investigated with different O/A ratio as well as
with number of stages of contact of aqueous and organic phases. Valuable information was obtained for the designing of an impurities
removal process for the production of pure cobalt with less trouble in the electrowinning circuit.
Abstract: It is important to remove manganese from water
because of its effects on human and the environment. Human
activities are one of the biggest contributors for excessive manganese
concentration in the environment. The proposed method to remove
manganese in aqueous solution by using adsorption as in carbon
nanotubes (CNT) at different parameters: The parameters are CNT
dosage, pH, agitation speed and contact time. Different pHs are pH
6.0, pH 6.5, pH 7.0, pH 7.5 and pH 8.0, CNT dosages are 5mg,
6.25mg, 7.5mg, 8.75mg or 10mg, contact time are 10 min, 32.5 min,
55 min, 87.5 min and 120 min while the agitation speeds are 100rpm,
150rpm, 200rpm, 250rpm and 300rpm. The parameters chosen for
experiments are based on experimental design done by using Central
Composite Design, Design Expert 6.0 with 4 parameters, 5 levels and
2 replications. Based on the results, condition set at pH 7.0, agitation
speed of 300 rpm, 7.5mg and contact time 55 minutes gives the
highest removal with 75.5%. From ANOVA analysis in Design
Expert 6.0, the residual concentration will be very much affected by
pH and CNT dosage. Initial manganese concentration is 1.2mg/L
while the lowest residual concentration achieved is 0.294mg/L,
which almost satisfy DOE Malaysia Standard B requirement.
Therefore, further experiments must be done to remove manganese
from model water to the required standard (0.2 mg/L) with the initial
concentration set to 0.294 mg/L.
Abstract: A method of collecting composition data and examining structural features of pearlite lamellae and the parent austenite at the growth interface in a 13wt. % manganese steel has been demonstrated with the use of Scanning Transmission Electron Microscopy (STEM). The combination of composition data and the structural features observed at the growth interface show that available theories of pearlite growth cannot explain all the observations.
Abstract: In this study, we sought to investigate the mercury
removal efficiency of manganese oxides from natural gas. The
fundamental studies on mercury removal with manganese oxides
sorbents were carried out in a laboratory scale fixed bed reactor at 30
°C with a mixture of methane (20%) and nitrogen gas laden with 4.8
ppb of elemental mercury. Manganese oxides with varying surface
area and crystalline phase were prepared by conventional precipitation
method in this study. The effects of surface area, crystallinity and
other metal oxides on mercury removal efficiency were investigated.
Effect of Ag impregnation on mercury removal efficiency was also
investigated. Ag supported on metal oxide such titania and zirconia as
reference materials were also used in this study for comparison. The
characteristics of mercury removal reaction with manganese oxide
was investigated using a temperature programmed desorption (TPD)
technique.
Manganese oxides showed very high Hg removal activity (about
73-93% Hg removal) for first time use. Surface area of the manganese
oxide samples decreased after heat-treatment and resulted in complete
loss of Hg removal ability for repeated use after Hg desorption in the
case of amorphous MnO2, and 75% loss of the initial Hg removal
activity for the crystalline MnO2. Mercury desorption efficiency of
crystalline MnO2 was very low (37%) for first time use and high (98%)
after second time use. Residual potassium content in MnO2 may have
some effect on the thermal stability of the adsorbed Hg species.
Desorption of Hg from manganese oxides occurs at much higher
temperatures (with a peak at 400 °C) than Ag/TiO2 or Ag/ZrO2.
Mercury may be captured on manganese oxides in the form of mercury
manganese oxide.
Abstract: Metal cutting is a severe plastic deformation process
involving large strains, high strain rates, and high temperatures.
Conventional analysis of the chip formation process is based on bulk
material deformation disregarding the inhomogeneous nature of the
material microstructure. A series of orthogonal cutting tests of AISI
1045 and 1144 steel were conducted which yielded similar process
characteristics and chip formations. With similar shear angles and cut
chip thicknesses, shear strains for both chips were found to range
from 2.0 up to 2.8. The manganese-sulfide (MnS) precipitate in the
1144 steel has a very distinct and uniform shape which allows for
comparison before and after chip formation. From close observations
of MnS precipitates in the cut chips it is shown that the conventional
approach underestimates plastic strains in metal cutting.
Experimental findings revealed local shear strains around a value of
6. These findings and their implications are presented and discussed.
Abstract: We succeeded to produce a high performance and flexible graphene/Manganese dioxide (G/MnO2) electrode coated on flexible polyethylene terephthalate (PET) substrate. The graphene film is initially synthesized by drop-casting the graphene oxide (GO) solution on the PET substrate, followed by simultaneous reduction and patterning of the dried film using carbon dioxide (CO2) laser beam with power of 1.8 W. Potentiostatic Anodic Deposition method was used to deposit thin film of MnO2 with different loading mass 10 – 50 and 100 μg.cm-2 on the pre-prepared graphene film. The electrodes were fully characterized in terms of structure, morphology, and electrochemical performance. A maximum specific capacitance of 973 F.g-1 was attributed when depositing 50μg.cm-2 MnO2 on the laser reduced graphene oxide rGO (or G/50MnO2) and over 92% of its initial capacitance was retained after 1000 cycles. The good electrochemical performance and long-term cycling stability make our proposed approach a promising candidate in the supercapacitor applications.