Abstract: MinC plays an important role in bacterial cell division
system by inhibiting FtsZ assembly. However, the molecular
mechanism of the action is poorly understood. E. coli MinC Nterminus
domain was purified and crystallized using 1.4 M sodium
citrate pH 6.5 as a precipitant. X-ray diffraction data was collected
and processed to 2.3 Å from a native crystal. The crystal belonged to
space group P212121, with the unit cell parameters a = 52.7, b = 54.0,
c = 64.7 Å. Assuming the presence of two molecules in the
asymmetric unit, the Matthews coefficient value is 1.94 Å3 Da-1,
which corresponds to a solvent content of 36.5%. The overall
structure of MinCN is observed as a dimer form through anti-parallel
ß-strand interaction.
Abstract: Vertical ZnO nanowire array films were synthesized
based on aqueous method for sensing applications. ZnO nanowires
were investigated structurally using X-ray diffraction (XRD) and
scanning electron microscopy (SEM). The gas-sensing properties of
ZnO nanowires array films are studied. It is found that the ZnO
nanowires array film sensor exhibits excellent sensing properties
towards O2 and CO2 at 100 °C with the response time shorter than 5
s. High surface area / volume ratio of vertical ZnO nanowire and high
mobility accounts for the fast response and recovery. The sensor
response was measured in the range from 100 to 500 ppm O2 and CO2
in this study.
Abstract: The characterisation of agro-wastes fibres for composite applications from Nigeria using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) has been done. Fibres extracted from groundnut shell, coconut husk, rice husk, palm fruit bunch and palm fruit stalk are processed using two novel cellulose fibre production methods developed by the authors. Cellulose apparent crystallinity calculated using the deconvolution of the diffractometer trace shows that the amorphous portion of cellulose was permeable to hydrolysis yielding high crystallinity after treatment. All diffratograms show typical cellulose structure with well-defined 110, 200 and 040 peaks. Palm fruit fibres had the highest 200 crystalline cellulose peaks compared to others and it is an indication of rich cellulose content. Surface examination of the resulting fibres using SEM indicates the presence of regular cellulose network structure with some agglomerated laminated layer of thin leaves of cellulose microfibrils. The surfaces were relatively smooth indicating the removal of hemicellulose, lignin and pectin.
Abstract: Residual dye contents in textile dyeing wastewater have complex aromatic structures that are resistant to degrade in biological wastewater treatment. The objectives of this study were to determine the effectiveness of nanoscale zerovalent iron (NZVI) to decolorize Reactive Black 5 (RB5) and Reactive Red 198 (RR198) in synthesized wastewater and to investigate the effects of the iron particle size, iron dosage and solution pHs on the destruction of RB5 and RR198. Synthesized NZVI was confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The removal kinetic rates (kobs) of RB5 (0.0109 min-1) and RR198 (0.0111 min-1) by 0.5% NZVI were many times higher than those of microscale zerovalent iron (ZVI) (0.0007 min-1 and 0.0008 min-1, respectively). The iron dosage increment exponentially increased the removal efficiencies of both RB5 and RR198. Additionally, lowering pH from 9 to 5 increased the decolorization kinetic rates of both RB5 and RR198 by NZVI. The destruction of azo bond (N=N) in the chromophore of both reactive dyes led to decolorization of dye solutions.
Abstract: Solar energy is the most “available", ecological and clean energy. This energy can be used in active or passive mode. The active mode implies the transformation of solar energy into a useful energy. The solar energy can be transformed into thermal energy, using solar collectors. In these collectors, the active and the most important element is the absorber, material which performs the absorption of solar radiation and, in at the same time, limits its reflection. The paper presents some aspects regarding the IR absorbing material – a type of cermets, used as absorber in the solar collectors, by X Ray Diffraction Technique (XRD) characterization.
Abstract: This study shows the effect of carbon towards
molybdenum carbide alloy when exposed to Microwave. This
technique is also known as Microwave Induced Alloying (MIA) for
the preparation of molybdenum carbide. In this study ammonium
heptamolybdate solution and carbon black powder were
heterogeneously mixed and exposed to microwave irradiation for 2
minutes. The effect on amount of carbon towards the produced alloy
on morphological and oxidation states changes during microwave is
presented. In this experiment, it is expected carbon act as a reducing
agent with the ratio 2:7 molybdenum to carbon as the optimum for
the production of molybdenum carbide alloy. All the morphological
transformations and changes in this experiment were followed and
characterized using X-Ray Diffraction and FESEM.
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 mechanical properties including flexural and
tensile of neat vinyl ester and polymer based on layered silicate
nanocomposite materials are discussed. The addition of layered
silicate into the polymer matrix increased the tensile and flexural
modulus up to 1 wt.% clay loading. The incorporation of more clay
resulted in decreasing the mechanical properties which was traced to
the existence of aggregation layers. Likewise, up to 1 wt.% clay
loading, the thermal behaviour showed significant improvements and
at higher clay loading the thermal pattern was reduced. The
aggregation layers imparted a negative impact on the overall
mechanical and thermal properties. Wide Angle X-ray Diffraction,
Scanning Electron Microscopy and Transmission Electron
Microscopy were utilised in order to characterise the interlamellar
structure of nanocomposites.
Abstract: Samples of CoFe2-xCrxO4 where x varies from 0.0 to 0.5 were prepared by co-precipitation route. These samples were sintered at 750°C for 2 hours. These particles were characterized by X-ray diffraction (XRD) at room temperature. The FCC spinel structure was confirmed by XRD patterns of the samples. The crystallite sizes of these particles were calculated from the most intense peak by Scherrer formula. The crystallite sizes lie in the range of 37-60 nm. The lattice parameter was found decreasing upon substitution of Cr. DC electrical resistivity was measured as a function of temperature. The room temperature thermoelectric power was measured for the prepared samples. The magnitude of Seebeck coefficient depends on the composition and resistivity of the samples.
Abstract: Hydrodesulfurization (HDS) of dibenzothiophene
(DBT) in a high pressure batch reactor was done at 320 °C on
CoMoS/Al2O3-B2O3 (4, 10, and 16 wt. % of Boria) using nhexadecane
as solvent, dimethyldisulfide (DMDS) in tetradecane as
sulfur agent, and stirring at 1000 rpm. The effects of boria were
investigated by using X-ray diffraction (XRD), Temperature
programmed desorption (TPD) of ammonia, and Brunauer-Emmet-
Teller (BET) experiments. The results showed that the catalyst
prepared with low boria content (4 wt. %) had HDS activity (in
pseudo first order kinetic constant basis) value ~1.45 times higher to
that of CoMoS/Al2O3 catalyst.
Abstract: The kinetics of palm oil catalytic cracking over
aluminum containing mesoporous silica Al-MCM-41 (5% Al) was
investigated in a batch autoclave reactor at the temperatures range of
573 – 673 K. The catalyst was prepared by using sol-gel technique
and has been characterized by nitrogen adsorption and x-ray
diffraction methods. Surface area of 1276 m2/g with average pore
diameter of 2.54 nm and pore volume of 0.811 cm3/g was obtained.
The experimental catalytic cracking runs were conducted using 50 g
of oil and 1 g of catalyst. The reaction pressure was recorded at
different time intervals and the data were analyzed using Levenberg-
Marquardt (LM) algorithm using polymath software. The results
show that the reaction order was found to be -1.5 and activation
energy of 3200 J/gmol.
Abstract: Spherical shaped magnetite (Fe3O4) and Au@Fe3O4
nanoparticles were successfully synthesized from Fe electrodes
immersed in water with CTAB surfactant and HAuCl4 solution using
simple method-pulsed plasma in liquid, without the use of dopants or
special conditions for stabilization. Vibrating sample magnetometer
indicated ferromagnetic behavior of particles at room temperature with
coercivity and saturation magnetization of (Hc=105 Oe, Ms=6.83
emu/g) for Fe3O4 and (Hc=175, Ms=3.56emu/g) for Au@Fe3O4
nanoparticles. Structure and morphology of nanoparticles were
characterized by X-ray Diffraction analysis and HR-TEM
measurements. The cytotoxicity of nanoparticles was indicated using a
XTT assay to be very low (cell viability: 98-89% with Fe3O4 and
99-91% for Au@Fe3O4 NPs).
Abstract: Solid dispersions (SD) of curcuminpolyvinylpyrrolidone
in the ratio of 1:2, 1:4, 1:5, 1:6, and 1:8 were
prepared in an attempt to increase the solubility and dissolution.
Solubility, dissolution, powder X-ray diffraction (XRD), differential
scanning calorimetry (DSC) and Fourier transform infrared
spectroscopy (FTIR) of solid dispersions, physical mixtures (PM)
and curcumin were evaluated. Both solubility and dissolution of
curcumin solid dispersions were significantly greater than those
observed for physical mixtures and intact curcumin. The powder
X-ray diffractograms indicated that the amorphous curcumin was
obtained from all solid dispersions. It was found that the optimum
weight ratio for curcumin:PVP K-30 is 1:6. The 1:6 solid dispersion
still in the amorphous from after storage at ambient temperature for 2
years and the dissolution profile did not significantly different from
freshly prepared.
Abstract: The crystallization kinetics and phase transformation
of SiO2.Al2O3.0,56P2O5.1,8CaO.0,56CaF2 glass have been
investigated using differential thermal analysis (DTA), x-ray
diffraction (XRD), and scanning electron microscopy (SEM). Glass
samples were obtained by melting the glass mixture at 14500С/120
min. in platinum crucibles. The mixture were prepared from
chemically pure reagents: SiO2, Al(OH)3, H3PO4, CaCO3 and CaF2.
The non-isothermal kinetics of crystallization was studied by
applying the DTA measurements carried out at various heating rates.
The activation energies of crystallization and viscous flow were
measured as 348,4 kJ.mol–1 and 479,7 kJ.mol–1 respectively. Value of
Avrami parameter n ≈ 3 correspond to a three dimensional of crystal
growth mechanism. The major crystalline phase determined by XRD
analysis was fluorapatite (Ca(PO4)3F) and as the minor phases –
fluormargarite (CaAl2(Al2SiO2)10F2) and vitlokite (Ca9P6O24). The
resulting glass-ceramic has a homogeneous microstructure, composed
of prismatic crystals, evenly distributed in glass phase.
Abstract: Using steelmaking slag as a raw material, aragonite superstructure product had been synthesized via an indirect CO2 mineral sequestration rout. It mainly involved two separate steps, in which the element of calcium is first selectively leached from steelmaking slag by a novel leaching media consisting of organic solvent Tributyl phosphate (TBP), acetic acid, and ultra-purity water, followed by enhanced carbonation in a separate step for aragonite superstructure production as well as efficiency recovery of leaching media. Based on the different leaching medium employed in the steelmaking slag leaching process, two typical products were collected from the enhanced carbonation step. The products were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), respectively. It reveals that the needle-like aragonite crystals self-organized into aragonite superstructure particles including aragonite microspheres as well as dumbbell-like spherical particles, can be obtained from the steelmaking slag with the purity over 99%.
Abstract: A diamond-like carbon (DLC) based solid-lubricant
film was designed and DLC films were successfully prepared using a
microwave plasma enhanced magnetron sputtering deposition
technology. Post-test characterizations including Raman
spectrometry, X-ray diffraction, nano-indentation test, adhesion test,
friction coefficient test were performed to study the influence of
substrate bias voltage on the mechanical properties of the W- and
S-doped DLC films. The results indicated that the W- and S-doped
DLC films also had the typical structure of DLC films and a better
mechanical performance achieved by the application of a substrate
bias of -200V.
Abstract: The systematic manipulations of shapes and sizes of
inorganic compounds greatly benefit the various application fields
including optics, magnetic, electronics, catalysis and medicine.
However shape control has been much more difficult to achieve.
Hence exploration of novel method for the preparation of differently
shaped nanoparticles is challenging research area. II-VI group of
semiconductor cadmium sulphide (CdS) nanostructure with different
morphologies (such as, acicular like, mesoporous, spherical shapes)
and of crystallite sizes vary from 11 to 16 nm were successfully
synthesized by chemical aqueous precipitation of Cd2+ ions with
homogeneously released S2- ions from decomposition of cadmium
sulphate (CdSO4) and thioacetamide (CH3CSNH2) by annealing at
different radiations (microwave, ultrasonic and sunlight) with matter
and systematic research has been done for various factors affecting
the controlled growth rate of CdS nanoparticles. The obtained
nanomaterials have been characterized by X-ray Diffraction (XRD),
Fourier Transform Infrared Spectroscopy (FTIR),
Thermogravometric (DSC-TGA) analysis and Scanning Electron
Microscopy (SEM). The result indicates that on increasing the
reaction time particle size increases but on increasing the molar ratios
grain size decreases.
Abstract: In this paper the combination of thermal oxidation and
electrochemical anodizing processes is used to produce titanium
oxide layers. The response of titanium alloy Ti6Al4V to oxidation
processes at various temperatures and electrochemical anodizing in
various voltages are investigated. Scanning electron microscopy
(SEM); X-Ray Diffraction (XRD) and porosity determination have
been used to characterize the oxide layer thickness, surface
morphology, oxide layer-substrate adhesion and porosity. In the first
experiment, samples modified by thermal oxidation process then
followed by electrochemical anodizing. Second experiment consists
of surfaces modified by electrochemical anodizing process and then
followed by thermal oxidation. The first method shows better
properties than other one. In second experiment, Surfaces modified
were achieved by thicker and more adherent thick oxide layers on
titanium surface. The existence of an electrochemical anodized oxide
layer did not improve the adhesion of thermal oxide layer. The high
temperature, thermal formation of an oxide layer leads to a coarse
oxide grain morphology and a complete oxidative particle. In
addition, in high temperature oxidation porosity content is increased.
The oxide layer of thermal oxidation and electrochemical anodizing
processes; on Ti–6Al–4V substrate was covered with different
colored oxide layers.
Abstract: This paper is concerned with the study of mineralogy
and engineering characteristics of soil materials derived from the
eastern part of Nile Delta. The clay minerals of the studied soil by
using X- ray diffraction are mainly illite (average 72.6 %) and
kaolinite (average 2.6 %), expandable portion in illite-smectite mixed
layer (average 7 %). Smectite is more abundant in fluviatile clays,
whereas kaolinite is more abundant in lagoonal clays. On the other
hand, illite and illite-smectite are more abundant in marine clays. The
geotechnical results show that the soil under study consists mainly of
about 0.3 % gravel, 5 % sand, 51.5 % silt and 42.2 % clay in average.
The average shrinkage limit attains 11 % whereas the average value
of the plasticity index is 23.4 %. The free swelling ranges from 40 %
to 75 % and has a value of 55 % giving an indication about the
inadequacy of such soil under foundations.
From a construction point of view, the soil under investigation
poses many problems even under light foundations due to the
swelling and shrinkage. Such swelling and shrinkage is due to the
high content of soil materials in the expandable clay minerals of illite
and smectite. Based on the results of the present and earlier studies,
trial application of soil stabilisation is recommended.
Abstract: ZnS nanoparticles of different size have been
synthesized using a colloidal particles method. Zns nanoparticles
prepared with capping agent (mercaptoethanol) then were
characterized using X-ray diffraction (XRD) and UV-Vis
spectroscopy. The particle size of the nanoparticles calculated from
the XRD patterns has been found in the range 1.85-2.44nm.
Absorption spectra have been obtained using UV-Vis
spectrophotometer to find the optical band gap and the obtained
values have been founded to being range 3.83-4.59eV. It was also
found that energy band gap increase with the increase in molar
capping agent solution.