Abstract: Segmentation is an important step in medical image
analysis and classification for radiological evaluation or computer
aided diagnosis. This paper presents the problem of inaccurate lung
segmentation as observed in algorithms presented by researchers
working in the area of medical image analysis. The different lung
segmentation techniques have been tested using the dataset of 19
patients consisting of a total of 917 images. We obtained datasets of
11 patients from Ackron University, USA and of 8 patients from
AGA Khan Medical University, Pakistan. After testing the algorithms
against datasets, the deficiencies of each algorithm have been
highlighted.
Abstract: The complexity of lignocellulosic biomass requires
a pretreatment step to improve the yield of fermentable sugars. The
efficient pretreatment of corn cobs using microwave and potassium
hydroxide and enzymatic hydrolysis was investigated. The
objective of this work was to characterize the optimal condition of
pretreatment of corn cobs using microwave and potassium
hydroxide enhance enzymatic hydrolysis. Corn cobs were
submerged in different potassium hydroxide concentration at varies
temperature and resident time. The pretreated corn cobs were
hydrolyzed to produce the reducing sugar for analysis. The
morphology and microstructure of samples were investigated by
Thermal gravimetric analysis (TGA, scanning electron microscope
(SEM), X-ray diffraction (XRD). The results showed that lignin
and hemicellulose were removed by microwave/potassium
hydroxide pretreatment. The crystallinity of the pretreated corn
cobs was higher than the untreated. This method was compared
with autoclave and conventional heating method. The results
indicated that microwave-alkali treatment was an efficient way to
improve the enzymatic hydrolysis rate by increasing its
accessibility hydrolysis enzymes.
Abstract: Silver nanoparticles were prepared by chemical reduction method. Silver nitrate was taken as the metal precursor and hydrazine hydrate as a reducing agent. The formation of the silver nanoparticles was monitored using UV-Vis absorption spectroscopy. The UV-Vis spectroscopy revealed the formation of silver nanopart├¡cles by exhibing the typical surface plasmon absorption maxima at 418-420 nm from the UV–Vis spectrum. Comparison of theoretical (Mie light scattering theory) and experimental results showed that diameter of silver nanoparticles in colloidal solution is about 60 nm. We have used energy-dispersive spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and, UV–Vis spectroscopy to characterize the nanoparticles obtained. The energy-dispersive spectroscopy (EDX) of the nanoparticles dispersion confirmed the presence of elemental silver signal no peaks of other impurity were detected. The average size and morphology of silver nanoparticles were determined by transmission electron microscopy (TEM). TEM photographs indicate that the nanopowders consist of well dispersed agglomerates of grains with a narrow size distribution (40 and 60 nm), whereas the radius of the individual particles are between 10 and 20 nm. The synthesized nanoparticles have been structurally characterized by X-ray diffraction and transmission high-energy electron diffraction (HEED). The peaks in the XRD pattern are in good agreement with the standard values of the face-centered-cubic form of metallic silver (ICCD-JCPDS card no. 4-0787) and no peaks of other impurity crystalline phases were detected. Additionally, the antibacterial activity of the nanopart├¡culas dispersion was measured by Kirby-Bauer method. The nanoparticles of silver showed high antimicrobial and bactericidal activity against gram positive bacteria such as Escherichia Coli, Pseudimonas aureginosa and staphylococcus aureus which is a highly methicillin resistant strain.
Abstract: Borate minerals have attracted considerable attention in the past years due to their structural chemistry and mechanical properties in several industries. Recently, increasing attention has been paid to the use of; synthetically produced magnesium borates as catalysts reinforcing material for plastics, the conversion of hydrocarbons, electro-conductive treating agent, anti-wear and anti-corrosion materials. Magnesium borates can be synthesized by several methods such as; hydrothermal and solid-state (thermal) processes. In this study the hydrothermal production method was applied at the modest temperature of 80C along with convenient crystal growth. Using MgCl2.6H2O, H3BO3, and NaOH as starting materials, 30, 60, 120, 240 minutes of reaction times were studied. After all, the crystal structure and the morphology of the products were examined by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). As a result the forms of Admontite and Mcallisterite minerals were synthesized.
Abstract: In this paper, Zinc Oxide (ZnO) thin films are deposited on glass substrate by sol-gel method. The ZnO thin films with well defined orientation were acquired by spin coating of zinc acetate dehydrate monoethanolamine (MEA), de-ionized water and isopropanol alcohol. These films were pre-heated at 275°C for 10 min and then annealed at 350°C, 450°C and 550°C for 80 min. The effect of annealing temperature and different thickness on structure and surface morphology of the thin films were verified by Atomic Force Microscopy (AFM). It was found that there was a significant effect of annealing temperature on the structural parameters of the films such as roughness exponent, fractal dimension and interface width. Thin films also were characterizied by X-ray Diffractometery (XRD) method. XRD analysis revealed that the annealed ZnO thin films consist of single phase ZnO with wurtzite structure and show the c-axis grain orientation. Increasing annealing temperature increased the crystallite size and the c-axis orientation of the film after 450°C. Also In this study, ZnO thin films in different thickness have been prepared by sol-gel method on the glass substrate at room temperature. The thicknesses of films are 100, 150 and 250 nm. Using fractal analysis, morphological characteristics of surface films thickness in amorphous state were investigated. The results show that with increasing thickness, surface roughness (RMS) and lateral correlation length (ξ) are decreased. Also, the roughness exponent (α) and growth exponent (β) were determined to be 0.74±0.02 and 0.11±0.02, respectively.
Abstract: Zinc borates can be used as multi-functional
synergistic additives with flame retardant additives in polymers. Zinc
borate is white, non-hygroscopic and powder type product. The most
important properties are low solubility in water and high dehydration
temperature. Zinc borates dehydrate above 290°C and anhydrous zinc
borate has thermal resistance about 400°C. Zinc borates can be
synthesized using several methods such as hydrothermal and solidstate
processes. In this study, the solid-state method was applied at
low temperatures of 600oC and 700oC using the starting materials of
ZnO and H3BO3 with several mole ratios. The reaction time was
determined as 4 hours after some preliminary experiments. After the
synthesis, the crystal structure and the morphology of the products
were examined by X-Ray Diffraction (XRD) and Fourier Transform
Infrared Spectroscopy (FT-IR). As a result the forms of ZnB4O7,
Zn3(BO3)2, ZnB2O4 were synthesized and obtained along with the
unreacted ZnO.
Abstract: The hybrid membranes containing inorganic materials in polymer matrix are identified as a remarkable family of proton conducting hybrid electrolytes. In this work, the proton conducting inorganic/organic hybrid membranes for proton exchange membrane fuel cells (PEMFCs) were prepared using polyvinyl alcohol (PVA), tetraethoxyorthosilane (TEOS) and heteropolyacid (HPA). The synthesized hybrid membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), Scanning electron microscopy (SEM) and Thermogravimetry analysis (TGA). The effects of heteropolyacid incorporation on membrane properties, including morphology and thermal stability were extensively investigated.
Abstract: The development of aid's systems for the medical
diagnosis is not easy thing because of presence of inhomogeneities in
the MRI, the variability of the data from a sequence to the other as
well as of other different source distortions that accentuate this
difficulty. A new automatic, contextual, adaptive and robust
segmentation procedure by MRI brain tissue classification is
described in this article. A first phase consists in estimating the
density of probability of the data by the Parzen-Rozenblatt method.
The classification procedure is completely automatic and doesn't
make any assumptions nor on the clusters number nor on the
prototypes of these clusters since these last are detected in an
automatic manner by an operator of mathematical morphology called
skeleton by influence zones detection (SKIZ). The problem of
initialization of the prototypes as well as their number is transformed
in an optimization problem; in more the procedure is adaptive since it
takes in consideration the contextual information presents in every
voxel by an adaptive and robust non parametric model by the
Markov fields (MF). The number of bad classifications is reduced by
the use of the criteria of MPM minimization (Maximum Posterior
Marginal).
Abstract: Magnetic and semiconductor nanomaterials exhibit
novel magnetic and optical properties owing to their unique size and
shape-dependent effects. With shrinking the size down to nanoscale
region, various anomalous properties that normally not present in bulk
start to dominate. Ability in harnessing of these anomalous properties
for the design of various advance electronic devices is strictly
dependent on synthetic strategies. Hence, current research has focused
on developing a rational synthetic control to produce high quality
nanocrystals by using organometallic approach to tune both size and
shape of the nanomaterials. In order to elucidate the growth
mechanism, transmission electron microscopy was employed as a
powerful tool in performing real time-resolved morphologies and
structural characterization of magnetic (Fe3O4) and semiconductor
(ZnO) nanocrystals. The current synthetic approach is found able to
produce nanostructures with well-defined shapes. We have found that
oleic acid is an effective capping ligand in preparing oxide-based
nanostructures without any agglomerations, even at high temperature.
The oleate-based precursors and capping ligands are fatty acid
compounds, which are respectively originated from natural palm oil
with low toxicity. In comparison with other synthetic approaches in
producing nanostructures, current synthetic method offers an effective
route to produce oxide-based nanomaterials with well-defined shapes
and good monodispersity. The nanocystals are well-separated with
each other without any stacking effect. In addition, the as-synthesized
nanopellets are stable in terms of chemically and physically if
compared to those nanomaterials that are previous reported. Further
development and extension of current synthetic strategy are being
pursued to combine both of these materials into nanocomposite form
that will be used as “smart magnetic nanophotocatalyst" for industry
waste water treatment.
Abstract: Novel Coconut oil nanofluids of various concentrations have been prepared through ultrasonically assisted sol-gel method. The structural and morphological properties of the copper oxide nanoparticle have been analyzed with respectively and it revealed the monoclinic end-centered structure of crystallite and shuttle like flake morphology of agglomerates. Ultrasonic studies have been made for the nanofluids at different temperatures. The molecular interactions responsible for the changes in acoustical parameter with respect to concentration and temperature are discussed.
Abstract: Electrospinning is a broadly used technology to obtain
polymeric nanofibers ranging from several micrometers down to
several hundred nanometers for a wide range of applications. It offers
unique capabilities to produce nanofibers with controllable porous
structure. With smaller pores and higher surface area than regular
fibers, electrospun fibers have been successfully applied in various
fields, such as, nanocatalysis, tissue engineering scaffolds, protective
clothing, filtration, biomedical, pharmaceutical, optical electronics,
healthcare, biotechnology, defense and security, and environmental
engineering. In this study, polyurethane nanofibers were obtained
under different electrospinning parameters. Fiber morphology and
diameter distribution were investigated in order to understand them
as a function of process parameters.
Abstract: Controlled modification of appropriate sharpness for
nanotips is of paramount importance to develop novel materials and
functional devices at a nanometer resolution. Herein, we present a
reliable and unique strategy of laser irradiation enhanced
physicochemical etching to manufacture super sharp tungsten tips
with reproducible shape and dimension as well as high yields
(~80%). The corresponding morphology structure evolution of
tungsten tips and laser-tip interaction mechanisms were
systematically investigated and discussed using field emission
scanning electron microscope (SEM) and physical optics statistics
method with different fluences under 532 nm laser irradiation. This
work paves the way for exploring more accessible metallic tips
applications with tunable apex diameter and aspect ratio, and,
furthermore, facilitates the potential sharpening enhancement
technique for other materials used in a variety of nanoscale devices.
Abstract: In this study, we report the synthesis and
characterization of nanohydroxyapatite (nHAp) in gelatin-starch
matrix via biomimetic method. Characterization of the samples was
performed using X-ray diffraction (XRD) and Fourier Transform
infrared spectroscopy (FT-IR). The Size and morphology of the
nHAp samples were determined using scanning and transmission
electron microscopy (SEM and TEM). The results reveal that the
shape and morphology of nHAp is influenced by presence of
biopolymers as template. Carbonyl and amino groups from gelatin
and hydroxyl from starch play crucial roles in HAp formation on the
surface of gelatin-starch.
Abstract: The necessity of updating the numerical models inputs, because of geometrical and resistive variations in rivers subject to solid transport phenomena, requires detailed control and monitoring activities. The human employment and financial resources of these activities moves the research towards the development of expeditive methodologies, able to evaluate the outflows through the measurement of more easily acquirable sizes. Recent studies highlighted the dependence of the entropic parameter on the kinematical and geometrical flow conditions. They showed a meaningful variability according to the section shape, dimension and slope. Such dependences, even if not yet well defined, could reduce the difficulties during the field activities, and also the data elaboration time. On the basis of such evidences, the relationships between the entropic parameter and the geometrical and resistive sizes, obtained through a large and detailed laboratory experience on steady free surface flows in conditions of macro and intermediate homogeneous roughness, are analyzed and discussed.
Abstract: Work is focused to the study of unburned carbon in
ash from coal (and wastes) combustion in 8 combustion tests at 3
fluidised-bed power station, at co-combustion of coal and wastes
(also at fluidized bed) and at bench-scale unit simulating coal
combustion in small domestic furnaces. The attention is paid to
unburned carbon contents in bottom ashes and fly ashes at these 8
combustion tests and to morphology of unburned carbons. Specific
surface area of coals, unburned carbons and ashes and the relation of
specific surface area of unburned carbon and the content of volatile
combustibles in coal were studied as well.
Abstract: The quest of providing more secure identification
system has led to a rise in developing biometric systems. Dorsal
hand vein pattern is an emerging biometric which has attracted the
attention of many researchers, of late. Different approaches have
been used to extract the vein pattern and match them. In this work,
Principle Component Analysis (PCA) which is a method that has
been successfully applied on human faces and hand geometry is
applied on the dorsal hand vein pattern. PCA has been used to obtain
eigenveins which is a low dimensional representation of vein pattern
features. Low cost CCD cameras were used to obtain the vein
images. The extraction of the vein pattern was obtained by applying
morphology. We have applied noise reduction filters to enhance the
vein patterns. The system has been successfully tested on a database
of 200 images using a threshold value of 0.9. The results obtained are
encouraging.
Abstract: The article deals with development, design and
implementation of a mathematical model of the human respiratory
system. The model is designed in order to simulate distribution of
important intrapulmonary parameters along the bronchial tree such as
pressure amplitude, tidal volume and effect of regional mechanical
lung properties upon the efficiency of various ventilatory techniques.
Therefore exact agreement of the model structure with the lung
anatomical structure is required. The model is based on the lung
morphology and electro-acoustic analogy is used to design the
model.
Abstract: The project describes the modeling of various
architectures mechatronics specifically morphologies of robots in an educational environment. Each structure developed by students of
pre-school, primary and secondary was created using the concept of
reverse engineering in a constructivist environment, to later be integrated in educational software that promotes the teaching of
educational Robotics in a virtual and economic environment.
Abstract: The present paper discusses the selection of process
parameters for obtaining optimal nanocrystallites size in the CuOZrO2
catalyst. There are some parameters changing the inorganic
structure which have an influence on the role of hydrolysis and
condensation reaction. A statistical design test method is
implemented in order to optimize the experimental conditions of
CuO-ZrO2 nanoparticles preparation. This method is applied for the
experiments and L16 orthogonal array standard. The crystallites size
is considered as an index. This index will be used for the analysis in
the condition where the parameters vary. The effect of pH, H2O/
precursor molar ratio (R), time and temperature of calcination,
chelating agent and alcohol volume are particularity investigated
among all other parameters. In accordance with the results of
Taguchi, it is found that temperature has the greatest impact on the
particle size. The pH and H2O/ precursor molar ratio have low
influences as compared with temperature. The alcohol volume as
well as the time has almost no effect as compared with all other
parameters. Temperature also has an influence on the morphology
and amorphous structure of zirconia. The optimal conditions are
determined by using Taguchi method. The nanocatalyst is studied by
DTA-TG, XRD, EDS, SEM and TEM. The results of this research
indicate that it is possible to vary the structure, morphology and
properties of the sol-gel by controlling the above-mentioned
parameters.
Abstract: Films of pure tin oxide SnO2 and in presence of
antimony atoms (SnO2-Sb) deposited onto glass substrates have
shown a sufficiently high energy gap to be transparent in the visible
region, a high electrical mobility and a carrier concentration which
displays a good electrical conductivity [1]. In this work, the effects of
polycrystalline silicon substrate on the optical properties of pure and
Sb doped tin oxide is investigated.
We used the APCVD (atmospheric pressure chemical vapour
deposition) technique, which is a low-cost and simple technique,
under nitrogen ambient, for growing this material. A series of SnO2
and SnO2-Sb have been deposited onto polycrystalline silicon
substrates with different contents of antimony atoms at the same
conditions of deposition (substrate temperature, flow oxygen,
duration and nitrogen atmosphere of the reactor). The effect of the
substrate in terms of morphology and nonlinear optical properties,
mainly the reflectance, was studied. The reflectance intensity of the
device, compared to the reflectance of tin oxide films deposited
directly on glass substrate, is clearly reduced on the overall
wavelength range. It is obvious that the roughness of the poly-c
silicon plays an important role by improving the reflectance and
hence the optical parameters.
A clear shift in the minimum of the reflectance upon doping level
is observed. This minimum corresponds to strong free carrier
absorption, resulting in different plasma frequency. This effect is
followed by an increase in the reflectance depending of the antimony
doping. Applying the extended Drude theory to the combining
optical and electrical obtained results these effects are discussed.