During
a normal day, the intensity of sunlight, as a vector, is measured. By
calculating variation of angle between sun’s ray and surface of the earth,
angular velocity of the Earth’s rotation at different time intervals is
determined. This angular velocity is not unchanging and traces back to the
variations in intensity of light emanating from the Sun.
Title
From
Hyperion to Photon, a brief survey in the timeline of photon
Author(s)
Hossien Hossieni, J. M. A.
Fatah, Sarwar Mohammad, Mohammad Naby
Journal
Vietnam Journal of Science
(VJS)
Date
Publicaton Date (Web): May
25, 2016
Webpage
DOI:
dx.doi.org/10.20328/vjsonline.2016.rr2
Abstract
We
present in this paper a chronological study on the main line of the
electromagnetic radiation throughout the history of mankind. This history is
divided into three distinct eras: pre-classical, classical, and modern era.
In pre-classical era, myths are studied starting with Hyperion (god of
lightning), extramission theory and Euclid principles. While in classical
era, the main focus is on classical theories of physics through introducing
the Maxwell equations and Huygens and Newton’s theories on light. In
addition, aspects of light via particle and wave theory are reviewed. Special
relativity, photoelectric effect and radiation in quantum mechanics are the
studied topics in the modern era. We present the advancement in photonic
science from last century till present time and show its influences on fields
such as laser, quantum field theory, holographs, LED and entanglement.
Title
Dynamic
coefficients calculations for high energetic positronsimplanted into a semi-crystalline polymer
target film
Author(s)
Jamal Abda , Mazin Elias ,
Laith Al-Ani and Loay George
Journal
Diyala Journal for Pure
Science
Vol. No. Year
Date of receipt 28\3\2015,
Date of acceptance 6\12\2015
Abstract
In
this work , Absorbed , backscattering and transmitted probability
coefficients has been calculated via Monte Carlo simulation technique PsMCS (
positronium Monte – Carlo Computer Simulation ) for a high energetic
positrons implanted normally into a semi finite Polytetrafluoroethylene
target ( PTFE ) with its two components. Comparison with available references
yields good quantitative agreement for dynamics factors.
Title
Monte
Carlo Dynamic Transmission Calculations For High Energetic Positrons
Implanted Into A Semi-Crystalline Polymer Target Film
(Polytetrafluoroethylene)
Author(s)
J.M.R.Abda
Journal
IJSR
- INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH
Vol. No. Year
Volume:
5,Issue: 1, January 2016, ISSN No. 2277-8179
Abstract
In
this work, backscattering and transmitted probability coefficients with mean
penetrating depth has been calculated via Monte Carlo simulation technique
PsMCS ( positronium Monte – Carlo Computer Simulation ) for positrons with
different energies starting by high energies and finishing with very slow
energy ( from 0.15MeV to 70 eV) ,implanted normally and with different angles
, into a semi finite Polytetrafluoroethylene target ( PTFE ) . Comparison
with available references yields good quantitative agreement for dynamics
factors.
Title
Neutronic
and Thermal – Hydraulic Calculations for The Conversion of BN-350
Author(s)
Jamal
Mohammed Rashid Abda
Journal
1st
International Conference of Natural Science (ICNS 2016) College of Basic
Education, Charmo University, 46023 Chamchamal, Sulaimani, Kurdistan-Iraq
Abstract
This
paper represents the neutronic and thermal-hydraulic calculations for the
conversion of BN-350 from 27% to 7% enriched Uranium fuel elements. Mixed
enrichment cores has been studied where low enrichment uranium (LEU) cores
fresh fuel elements substitute gradually the high enrichment uranium (HEU)
depleted fuel elements in the equilibrium core. Thermal hydraulic
calculations have been carried out to determine changes in the
characteristics of the converted reactor during steady state conditions and transient
response to a coolant flow loss (LOCA).
Title
Determination
of 222Rn and 238U Concentrations in Some Selected Samples of Rock for
Sulaimani Area (Kurdistan Region-Iraq)
Author
Kamal
O. Abdullah
Journal
JZS
( Journal of Zankoy Sulaimani)
Part
A – Vol. 17-No. 4 ( Dec. 2015)
Abstract
Different
rock samples collected from the Mountains located to the west and north of
Sulaimani district. Solid state nuclear track detector technique, CR-39
passive detectors included, is used for analyzing concentrations Radon. The
uranium concentrations determined from the secular equilibrium between
uranium and radon activity. The concentrations of Radon and Uranium have been
calculated. The maximum and the minimum concentrations determined (19632.904
± 74.605 and 153789.072 ± 584.398)Bq/m3for Radon and
(1.289±0.619 ppm, 10.094±4.854 ppm) for uranium, respectively. The higher
concentration values of both Byara (Mountain of Balkha) and Penjween is due
to sample rocks formation compared to the values appeared from Ranya and
Chaqchaq regions. The highest annual effective dose was 0.8µSv/hr, which is
higher than the value 1mSv ~ 0.114 µSv/hr recommended by the International
Commission on Radiological ProtectionICRP.
Title
Indoor
Radon Concentration Measurement in Cement Factories in Sulaimani City
(Kurdistan region-Iraq)
Authors
Kamal O. Abdullah, Kharman
A. Faraj and Adil M. Hussein
Journal
European Journal of
Scientific Research
ISSN 1450-216X /
1450-202X
Vol. 135 No 1 October,
2015, pp.41-46
Abstract
Measurement
of radon level in cement factories (Tasluja, Mass and Bazyan) in Sulaimani
governorate was done by using Solid State Nuclear Track Detector technique.
In this study, CR-39 plastic detectors inside a dosimeter chamber have been
put in some selected places in the three factories like Crusher, Correction
stores, Raw Mill (Grinding Mill), Preheater (Tower), Clinker,….. .The average
value of radon concentration in the factoriesTasluja, Mass and Bazyan were
(98.320±9.910,102.816±10.137, 116.714±10.796) Bq/m3, respectively, and the
minimum value of radon concentration was (47.982±4.438) Bq/m3 and the maximum
value was (222.138±20.547) Bq/m3, comparing the values with the standard
world values from Environmental Protection Agency (EPA) the maximum value is
some higher which was appeared in the correctionstore of Bazyanfactory due to
adding in this section some type of materials as Sand, Iron, Clay, Gypsum,
Limestone,… may causes to high value of uranium and radon in this section.
Title
Cavity-Photon
Controlled Thermoelectric Transport through a Quantum Wire
Author(s)
Nzar Rauf Abdullah,
Chi-Shung Tang, Andrei Manolescu, and Vidar Gudmundsson
We
investigate the influence of a quantized photon field on thermoelectric
transport of electrons through a quantum wire embedded in a photon cavity.
The quantum wire is connected to two electron reservoirs at different
temperatures leading to a generation of a thermoelectric current. The
transient thermoelectric current strongly depends on the photon energy and
the number of photons initially in the cavity. Two different regimes are
studied, off-resonant and resonant polarized fields, with photon energy
smaller than, or equal to the energy spacing between some of the lowest
states in the quantum wire. We observe that the current is inverted for the
off-resonant photon field due to participation of photon replica states in
the transport. A reduction in the current is recorded for the resonant photon
field, a direct consequence of the Rabi-splitting.
Title
Cavity-photon
contribution to the effective interaction of electrons in parallel quantum
dots
Author(s)
Vidar Gudmundsson, Anna
Sitek, Nzar Rauf Abdullah, Chi-Shung Tang and Andrei Manolescu
A
single cavity photon mode is expected to modify the Coulomb interaction of an
electron system in the cavity. Here we investigate this phenomena in a
parallel double quantum dot system. We explore properties of the closed
system and the system after it has been opened up for electron transport. We
show how results for both cases support the idea that the effective
electron-electron interaction becomes more repulsive in the presence of a
cavity photon field. This can be understood in terms of the cavity photons
dressing the polarization terms in the effective mutual electron interaction
leading to nontrivial delocalization or polarization of the charge in the
double parallel dot potential. In addition, we find that the effective
repulsion of the electrons can be reduced by quadrupolar collective
oscillations excited by an external classical dipole electric field.
Title
Analytical
derivations of single-particle matrix elements in nuclear shell model
Author(s)
Aziz H. Fatah, R. A.
Radhi, and Nzar Rauf Abdullah
Journal
Communication in
Theoretical Physics
Vol. No. Year
Accepted for publication,
In press (2016)
Webpage
Abstract
We
propose a new analytical method to calculate single particle matrix elements
used in atomic and nuclear physics. We show seven different formulas of
matrix elements of the operator $f(r)d_r^{m}$ where
$f(r)=r^{\mu},r^{\mu}j_J(qr), V(r)$ corresponding to the Gaussian and the
Yukawa potentials used in nuclear shell models and nuclear structure. In
addition, we take into account a general integral formula of the matrix
element $\left\langle n'\, l'\left|f(r)\, d_{r}^{(m)} \right|n\,
l\right\rangle$ that covers all seven matrix elements obtained analytically.
Title
Optical
and structural investigation of synthesized PVA/PbS nanocomposites
Author(s)
Omed Gh. Abdullah, Dana A.
Tahir, K. Kadir
Name of
Journals
Journal of Materials
Science: Materials in Electronics
Polymer
nanocomposite based on polyvinyl alcohol (PVA) and lead sulfide (PbS) in the
average radius of (1.88-2.23) nm, have been synthesized using the chemical
reduction rote and solution casting technique for different concentrations of
PbS. The characterization of the polymer nanocomposite films were carried out
using UV-Visible Spectroscopy, SEM, and XRD. The effect of various
concentration of PbS NP on the optical properties of the composite has been
studied to understand the optimum conditions for the synthesis process. The
nanocomposite film shows high UV and visible light absorptions in the
wavelength range of (200-500) nm, which correspond to the characteristics of
the PbS NPs. The significant decreasing trend of the direct allowed band gap
of the nanocomposite was observed upon increasing the Pb source
concentration, from (6.27 eV) for pure PVA to (2.34 eV) for 0.04M PbS
concentration, which is much higher than the energy gap of bulk PbS value
(0.41 eV). The calculated values of the static refractive index of Cauchy
dispersion model were in the range of (1.09-1.20). X-ray diffraction analysis
confirmed the cubic nanocrystalline PbS phase formation.
Title
In-situ
synthesis of PVA/HgS nanocomposite films and tuning optical properties
Author(s)
Omed Gh. Abdullah, Yahya
A.K. Salman, Salwan A. Saleem
Name of
Journals
Physics and Materials
Chemistry
Vol. No. Year
Vol. 3, No. 2, pp. 18-24,
(2015)
ISSN
2372-7098 (Print) 2372-7101 (Online)
Publisher
Springer
Science& Education
DOI
DOI:10.12691/pmc-3-2-1
Webpage
http://www.sciepub.com/journal/PMC
Abstract
Polymer
based nanocomposite films of polyvinyl alcohol (PVA) doped with mercury
sulfide (HgS) were prepared via in-situ chemical reduction and the solution
cast methods, with different HgS concentrations, in order to study the effect
of HgS content on optical properties of PVA. The nanocomposites films were
characterized using FTIR, XRD, and SEM. The UV-Visible absorption spectra in
the wavelength range (190–1100) nm were analyzed in terms of absorption
formula for non-crystalline materials. The band gap and the fundamental
optical constants of the prepared samples have been investigated and showed a
clear dependence on the HgS concentration. The observed value of band gap for
pure polyvinyl alcohol is about 6.27 eV and decreases to a value 4.88 eV for
the film of 0.04M HgS content. The refractive index and consequently the
related dispersion parameters of PVA and PVA/HgS nanocomposite versus HgS
content have been determined and explained using Wemple-DiDomenico single
oscillator model.
Title
Electrical
conductivity and dielectric characteristics of in-situ prepared PVA/HgS
nanocomposite films
Author(s)
Omed Gh. Abdullah, Yahya
A.K. Salman, Salwan A. Saleem
Name of
Journals
Journal of Materials
Science: Materials in Electronics
Polyvinyl
alcohol (PVA) and mercury sulfide (HgS) polymer nanocomposite were prepared
using the solution casting and the in-situ chemical reduction of mercury
nitrate (Hg(NO3)2) and sodium sulfide (Na2S) in aqueous solutions of PVA as
capping for different molar content of Hg(NO3)2 and Na2S. The nanocomposites
films were characterized by Fourier Transform Infrared (FTIR), X-ray
diffraction (XRD), and scanning electron microscopy (SEM). The XRD results
for the nanoparticles revealed the hexagonal structure of the HgS, (α-phase).
The influence of embedded HgS nanoparticles on the conductivity and
dielectric properties of Polyvinyl Alcohol (PVA) films are investigated, over
the frequency range 1 KHz to 1 MHz, and the temperature range (30 − 110) oC.
The variation of ac-conductivity with a frequency of the films follows
Jonscher's universal power law and found to be increased with increasing
temperature, frequency and nanoparticle content. The variation of frequency
exponent (s) indicated that the conduction mechanism was correlated barrier
hopping (CBH) model. The dielectric constant (ε'), and dielectric loss (ε'')
was found to decrease with increasing frequency, but increase with increasing
temperature and HgS nanoparticles content. The dc-conductivity (σ_dc)
increase with increase of HgS concentration, and follows Arrhenius behavior
in the investigated temperature region.
Title
Synthesis,
Structural and Optical Characterization of MgO Nanocrystalline Embedded in
PVA Matrix
Author(s)
Shahbaa F. Bdewi, Omed Gh.
Abdullah, Bakhtyar K. Aziz, Ayad A.R. Mutar
Name of
Journals
Journal of Inorganic and
Organometallic Polymers and Materials
Nano-magnesium
oxide (MgO) was prepared by wet chemical method using magnesium chloride and
sodium hydroxide as precursors and soluble gelatin as stabilizing agent in
this paper. The synthesized nano MgO was characterized by XRD, SEM, and FTIR.
The results showed that the size of nano-MgO was about 20.62 nm. Polyvinyl
alcohol (PVA) polymer based nanocomposites, with different concentrations of
MgO (1, 2, 3, 4 wt%), have been prepared using solvent casting technique. The
results of SEM revealed that the MgO nanoparticles are uniformly distributed
in PVA polymer matrix. FTIR analysis evidently saw the interaction between
MgO with hydroxyl group of PVA through hydrogen bonding. The influences of
MgO nanoparticle on the optical characterisation of PVA have been considered
using UV-Vis-NIR spectroscopy. Energy band gap and tail of localized state of
PVA/MgO nanocomposites have been calculated by using Tauc and Urbach
relations, respectively. The band gap of the nanocomposites samples decreases
as MgO Wt% increases. Wemple-DiDomenico single-oscillator model has been
applied to analyze the dispersion of the refractive index of the films, and
the dispersion parameters are calculated to obtain the information about
disorder degree.
In
this work silver sulfide (Ag2S) has been synthesized inside the PVA polymer
by in situ chemical reduction method. The UV-Visible spectrophotometer was
used to study the optical properties of the prepared composite samples. The
absorption spectra reveal the influence of Ag2S particles on optical behavior
of PVA. There is an increase in refractive index of the samples contains Ag2S
filler, and exhibits a dispersion behavior. The extinction coefficients of
the composite samples are higher than that of pure PVA. The linear
relationship between the refractive index at high wavelength region and Ag2S
concentration was observed, indicating homogeneous dispersion of the filler
in the PVA matrix. The absorption coefficient shifts to lower photon energy
at higher Ag2S concentration, in which the optical band gap will reduce.
Title
Tuning
the absorption of ultraviolet spectra and optical parameters of aluminum
doped PVA based solid polymer composites
Author(s)
Shujahadeen B. Aziz,
Hameed M. Ahmed, Ahang M. Hussein, Awder B. Fathulla, Rawaz M. Wsw, Rekawt T.
Hussein
Journal
Journal of Materials
Science: Materials in Electronics
Vol. No. Year
October 2015, Volume 26,
Issue 10, pp 8022-8028
Abstract
In
this research work PVA:xAl (0.01 ≤ x ≤ 0.05) based solid polymer composites
have been prepared by solution cast technique. The transmittances of the
samples are decreased with increasing Al powder concentration. The absorption
spectra of the samples are shifted to higher wavelengths which indicate their
importance for shielding. The increase of absorption intensity in UV region
was observed. The clear shift of absorption edge upon the addition of Al
powder content indicated the decrease of energy band gap. The increase of
extinction coefficient at high wavelengths for the samples containing Al
powder revealed the loss of photon energy. The refractive indexes of the
doped samples are increased compared to that of pure PVA. The linear
relationship between the refractive index and volume fraction indicates a
good dispersion of Al powder in PVA host polymer. The direct optical band gap
measured from the plot of (αhυ)2 versus photon energy (hυ) showed a
decreasing trend with increase of Al content. The Urbach energy was found to
increase with increasing aluminum concentration. The complex optical
dielectric functions were used to determine the type of electron transition.
Title
Modifying
Poly(Vinyl Alcohol) (PVA) from Insulator to Small-Bandgap Polymer: A Novel
Approach for Organic Solar Cells and Optoelectronic Devices
Author(s)
Shujahadeen B. Aziz
Journal
Journal of Electronic
Materials
Vol. No. Year
January 2016, Volume 45,
Issue 1, pp 736-745
Abstract
An
innovative method has been used to reduce the bandgap of poly(vinyl alcohol)
(PVA) polymer by addition of a nontoxic, inexpensive, and environmentally
friendly material. The resulting materials are small-bandgap polymers, hence
opening new frontiers in green chemistry. The doped PVA films showed a wide
range of light absorption of the solar spectrum from 200 nm to above 800 nm.
Nonsharp absorption behavior versus wavelength was observed for the samples.
The refractive index exhibited a wide range of dispersion. Shift of the
absorption edge from 6.2 eV to 1.5 eV was observed. The energy bandgap of PVA
was diminished to 1.85 eV upon addition of black tea extract solution, lying
in the range of small-bandgap polymers. Increase of the optical dielectric
constant was observed with increasing tea solution addition. The results
indicate that small-bandgap PVA with good film-forming ability could be
useful in terms of cost–performance tradeoff, solving problems of short
lifetime, cost, and flexibility associated with conjugated polymers. The
decrease of the Urbach energy upon addition of black tea extract solution
indicates modification of PVA from a disordered to ordered material. X-ray
diffraction results confirm an increase of the crystalline fraction in the
doped samples.
Title
Study
of electrical percolation phenomenon from the dielectric and electric modulus
analysis
Author(s)
Shujahadeen B. Aziz
Journal
Bulletin of Materials Science
Vol. No. Year
October 2015, Volume 38, Issue 6, pp 1597-1602
Abstract
Chitosan
: AgI solid polymer composite films have been prepared by the well-known
solution cast technique. Electrical impedance spectroscopy was used to
investigate the electrical percolation threshold phenomenon in this work. A
wide dispersion can be seen in dielectric constant spectra at low
frequencies. The dielectric constant at selected frequencies as a function of
AgI concentration indicates the occurrence of electrical percolation
threshold via the appearance of two distinguishable regions. The behaviour of
dielectric constant and DC conductivity vs. AgI concentration are almost the
same at low and high filler concentrations. The steep increase of dielectric
constant and DC conductivity from 5 to 10 wt% of AgI was observed and a
plateau was achieved from 10 to 20 wt% of AgI. The pattern of real part of
electric modulus (M′) at selected frequencies is similar to dielectric
constant. The existence of distinct peaks in M′′ spectra with no
corresponding peaks in ε′′ spectra indicated that ionic and polymer segmental
motions are strongly coupled. Argand plots of M′′ vs. M′ was used to detect
the relaxation type process. The Argand plots at different temperatures
exhibit incomplete semicircular arc with a diameter below the real axis.
Title
In
Situ Synthesis of CuS Nanoparticle with a Distinguishable SPR Peak in NIR
Region
Author(s)
Shujahadeen B. Aziz*,1,
Rebar T. Abdulwahid2 , Hazhar A. Rsaul3, Hameed M. Ahmed4
Journal
Journal of Materials
Science: Materials in Electronics
Vol. No. Year
May 2016, Volume 27, Issue
5, pp 4163-4171
Abstract
In
this article we report the synthesis of CuS nanoparticle with distinguishable
surface plasmonic resonance (SPR) peaks in near infrared region. For this
purpose in situ synthesis (one-step fabrication) has been used to prepare CuS
nanoparticles in PMMA polymer matrix at room temperature. The X-ray
diffraction spectrum confirms the formation of CuS nanoparticles. The
transmittance spectra of nano-composite samples reveal that the samples have
a good transparency. The absorption spectra show a broad absorption peak in
the wavelength region from 570 to 980 nm which is a characteristic SPR peak
for CuS nanoparticle. An increase of refractive index was observed for the
samples containing CuS nanoparticles. The linear relationship between the
refractive index and volume fraction was observed. The appearance of SPR peak
in refractive index spectra was attributed to CuS nanoparticles. Shifting of
absorption edge to lower photon energy has been observed for nano-composite
samples. The direct energy bandgap of nano-composite samples are reduced
compare to pure PMMA polymer. The plot between the direct energy band gap and
refractive index reveals that the decrease in bandgap energy is associated
with the increase in index of refraction. The increase of optical dielectric
constant can be ascribed to the formation of CuS nanoparticles. The low band
gap of CuS nanoparticles in the present work reveals their importance for
applications in optoelectronic devices.
Title
Role
of Dielectric Constant on Ion Transport: Reformulated Arrhenius Equation
In
this research work solid and nanocomposte polymer electrolytes based on
chitosan has been prepared by solution cast technique. The XRD results reveal
the occurrence of complexation between chitosan (CS) and the LiTf salt. The
deconvolution of the diffractogram of nanocomposite solid polymer
electrolytes demonstrates the increase of amorphous domain with increasing
alumina content up to 4 wt.%. Further incorporation of alumina nanoparticles
(6 to 10 wt.% Al2O3) results in crystallinity increase (large crystallite
size). The morphological (SEM and EDX) analysis well supported the XRD
results. Similar trends of DC conductivity and dielectric constant with Al2O3
concentration was explained. The TEM images were used to explain the
phenomena of space charge and blocking effects. The reformulated Arrhenius
equation ( ) was proposed from the smooth exponential behavior of DC
conductivity versus dielectric constant at different temperatures. The more
linear behavior of DC conductivity versus 1000/(ɛ'×T) reveals the crucial
role of dielectric constant in Arrhenius equation. The drawbacks of Arrhenius
equation can be understood from the less linear behavior of DC conductivity
versus 1000/T. The relaxation processes has been interpreted in terms of
Argand plots.
Title
Electrical
impedance and conduction mechanism analysis of biopolymer electrolytes based
on methyl cellulose doped with ammonium iodide
Author(s)
N. S. Salleh, Shujahadeen
B. Aziz, Z. Aspanut , M. F. Z. Kadir
Journal
Ionics
Vol. No. Year
DOI:10.1007/s11581-016-1731-0
(This all he wrote)
Abstract
In
the present study, the potential of methyl cellulose (MC) as biopolymer
electrolyte (BPE) will be studied extensively by means of conductivity and
the conduction mechanism. BPE films based on MC doped with ammonium iodide
(NH4I) salt were prepared by solution-casting method. X-ray diffraction (XRD)
explains that the conductivity enhancement of the electrolytes is affected by
the degree of crystallinity. Field emission scanning electron microscopy
(FESEM) analysis shows the difference in the electrolyte’s surface with
respect to NH4I. On addition of 40 wt.% of NH4I, the highest room temperature
conductivity of (5.08 ± 0.04) × 10−4 S cm−1 was achieved. The temperature
dependence relationship for the salted electrolyte was found to obey the
Arrhenius rule where R2 ∼1 from which the activation energy (E a) was
evaluated. The dielectric study analyzed using complex permittivity ε* for
the sample with the highest conductivity at elevated temperature shows a non-
Debye behavior. These salted electrolytes follow the correlated barrier
hopping (CBH) model.
Title
A sensing mechanism for the detection of
carbon nanotubes using selective photoluminescent probes based on ionic
complexes with organic dyes
Author(s)
Allsop, T., Arif, R.,
Neal, R., Kalli, K., Kundrát, V., Rozhin, A., Culverhouse , P. & Webb, D.
J.
Journal
Light: Science &
Applications
Vol. No. Year
vol. 5, no.2, February 2016
Webpage
http://dx.doi.org/10.1038/lsa.2016.36
Abstract
The multifunctional properties of carbon
nanotubes (CNTs) make them a powerful platform for unprecedented innovations
in a variety of practical applications. As a result of the surging growth of
nanotechnology, nanotubes present a potential problem as an environmental
pollutant, and as such, an efficient method for their rapid detection must be
established. Here, we propose a novel type of ionic sensor complex for
detecting CNTs – an organic dye that responds sensitively and selectively to
CNTs with a photoluminescent signal. The complexes are formed through Coulomb
attractions between dye molecules with uncompensated charges and CNTs covered
with an ionic surfactant in water. We demonstrate that the photoluminescent
excitation of the dye can be transferred to the nanotubes, resulting in
selective and strong amplification (up to a factor of 6) of the light
emission from the excitonic levels of CNTs in the near-infrared spectral
range, as experimentally observed via excitation-emission photoluminescence
(PL) mapping. The chirality of the nanotubes and the type of ionic surfactant
used to disperse the nanotubes both strongly affect the amplification; thus,
the complexation provides sensing selectivity towards specific CNTs.
Additionally, neither similar uncharged dyes nor CNTs covered with neutral
surfactant form such complexes. As model organic molecules, we use a family
of polymethine dyes with an easily tailorable molecular structure and,
consequently, tunable absorbance and PL characteristics. This provides us
with a versatile tool for the controllable photonic and electronic
engineering of an efficient probe for CNT detection.
Title
Photonic
gas sensors exploiting directly the optical properties of hybrid carbon
nanotube localized surface plasmon structures
Author(s)
Allsop, T., Arif, R.,
Neal, R., Kalli, K., Kundrát, V., Rozhin, A., Culverhouse , P. & Webb, D.
J.
Journal
Light: Science &
Applications
Vol. No. Year
vol. 5, no.2, February 2016
Webpage
http://dx.doi.org/10.1038/lsa.2016.36
Abstract
We
investigate the modification of the optical properties of carbon nanotubes
(CNTs) resulting from a chemical reaction triggered by the presence of a
specific compound (gaseous carbon dioxide (CO2)) and show this mechanism has
important consequences for chemical sensing. CNTs have attracted significant
research interest because they can be functionalized for a particular
chemical, yielding a specific physical response which suggests many potential
applications in the fields of nanotechnology and sensing. So far, however,
utilizing their optical properties for this purpose has proven to be
challenging. We demonstrate the use of localized surface plasmons generated
on a nanostructured thin film, resembling a large array of nano-wires, to
detect changes in the optical properties of the CNTs. Chemical selectivity is
demonstrated using CO2 in gaseous form at room temperature. The demonstrated
methodology results additionally in a new, electrically passive, optical
sensing configuration that opens up the possibilities of using CNTs as
sensors in hazardous/explosive environments.
Title
High
Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer
Composite Saturable Absorber
Author(s)
Chernysheva, M., Mou, C.,
Arif, R., Al Araimi, M., Rummeli, M., Turitsyn, S. & Rozhin
Journal
Nature/ Scientific Reports
Vol. No. Year
vol. 6, April 2016
Webpage
http://dx.doi.org/10.1038/srep24220
Abstract
We
have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL)
with a ‘Yin-Yang’ all-fibre cavity scheme based on a combination of nonlinear
optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM).
Unidirectional lasing operation has been achieved without any intracavity
isolator. By using a carbon nanotube polymer composite based saturable
absorber (SA), we demonstrated the laser output power of ~197 mW and pulse
energy of 1.7 μJ. To the best of our knowledge, this is the highest output
power from a nanotube polymer composite SA based Q-switched Thulium doped
fibre laser.
Title
Carbon
nanotubes for ultrafast fibre lasers
Author(s)
Chernysheva, M., Rozhin,
A., Fedotov, Y., Mou, C., Arif, R., Kobtsev, S. M., Dianov, E. M. &
Turitsyn, S.
Carbon
nanotubes (CNTs) possess both remarkable optical properties and high
potential for integration in various photonic devices. We overview, here,
recent progress in CNT applications in fibre optics putting particular
emphasis on fibre lasers. We discuss fabrication and characterisation of
different CNTs, development of CNT-based saturable absorbers (CNT-SA), their
integration and operation in fibre laser cavities putting emphasis on
state-of-the-art fibre lasers, mode locked using CNT-SA. We discuss new
design concepts of high-performance ultrafast operation fibre lasers covering
ytterbium (Yb), bismuth (Bi), erbium (Er), thulium (Tm) and holmium
(Ho)-doped fibre lasers.
Title
High
chaotic spiking rate in a closed loop semiconductor laser with optical
feedback
Author(s)
Banaz O. Rasheed, Parekhan
M. Aljaff , Kais A. Al Naimee , Mahdi H. Al Hasani, Riccardo Meucci
We
investigate experimentally and numerically the existence of fast chaotic
spiking in the dynamics of a
semiconductor laser with ac-coupled optical feedback. The observed dynamics
is chaotic in the explored
range of both bias current optical feedback strength. The effects of a
modulation applied to the bias current
are also investigated. We eventually indicate that the observed chaotic
dynamics is a good candidate
to hide information to satisfy secure communications.
Assessment of Rn and U Concentrations in the Soil of Qadafery, Kalar and Zarayan Located in Sulaimani Governorate of Kurdistan Region- Iraq” in the journal American Journal of Environmental Protection (AJEP), Vol. 1, Issue 4, Page 40-44, 2015. (Kamal O. Abdullah, Salar Z. Muhammedand Adil M. Husain)
Measurement of 222Rn Concentrations in the Air of Qaysery Naqeeb Bazaar Located in Sulaimani Governorate of Kurdistan Region-Iraq”, Journal of Zankoy Sulaimani-part A (JZS), Vol.17, Issue 2, 2015.( Kamal O. Abdullah, Ali H. Ahmed and Salahaddin A. Ahmed)
Entanglement, the greatest mystery in physics by Amir D. Aczel, translated by Hossien Hossieni and Dr.Omed G. 2015
Physics and beyond by Werner Heisenberg translated by Hossien Hossieni 2015
From Sky to String by Hossien Hossieni in Kurdish 2015
Rauf KM, Hossieni H, Arkan Z, Sarkawt D (2015) Distribution of Moons in the Solar System. J Astrophys Aerospace Technol 3: 120
Rauf KM, Hossieni H, Ahmad SS, Ali H, Kawa H(2015) Study of the Improvement of Noise Pollution in University of Sulaimani in both New and Old Campus. J Pollut Eff Cont 3: 143
Rauf KM, Hossieni H , Majeed D and Ibrahim R, Comparing the Atmospheric Compositions of All Planets and Giant Moons in Solar System, Astrobiol Outreach Volume 3 • Issue 3 • 1000136 Aug 2015
KM Rauf, H Hossieni, SS Ahmad, S Jamal, A Hussien, Comparison of the Noise Pollution in Sulaimani City between the Years 2009 and 2014 “”, J Pollut Eff Cont, 2015
Omed Gh. Abdullah, Dlear R. Saber, Sherzad A. Taha, "The Optical Characterization of Polyvinyl Alcohol: Cobalt Nitrate Solid Polymer Electrolyte Films", Advanced Materials Letters, Vol. 6, Issue 2, pp. 153-157, (2015).
Omed Gh. Abdullah, Dlear R. Saber, Luqman O. Hamasalih, "Complexion Formation in PVA/PEO/CuCl2 Solid Polymer Electrolyte", Universal Journal of Materials Science, Vol. 3, No.1, pp. 1-5, (2015).
Omed Gh. Abdullah, "Synthesis and optical band gap investigation of PVA/CdS nanocomposite films", Journal of Zankoy Sulaimani, Vol. 17A, No.1, pp. 185-192, (2015).
Omed Gh. Abdullah, Shujahadeen B. Aziz, Khalid M. Omer, Yousif M. Salih, "Reducing the optical band gap of polyvinyl alcohol (PVA) based nanocomposite", Journal of Materials Science: Materials in Electronics, Vol. 26, Issue 7, pp. 5303-5309, (2015).
Omed Gh. Abdullah, Dana A. Tahir, Dlear R. Saber, "Optical properties of the synthesized Cr2S3 nanoparticles embedded in polyvinyl alcohol", ARO, The Scientific Journal of Koya University, Vol. 3, No. 1, pp. 45-49, (2015)
Omed Gh. Abdullah, Dana A. Tahir, K. Kadir, "Optical and structural investigation of synthesized PVA/PbS nanocomposites", Journal of Materials Science: Materials in Electronics, Vol. 26, Issue 9, pp. 6939-6944, (2015)
Standard structure for laboratory reports and scientific research, by Awara Rasul Muhammad, 2015 (in Kurdish)
Transistors and some of its applications, by Awara Rasul Muhammad, 2015 (in Kurdish)
Some relevant information regarding how to study and answer in examinations, by Awara Rasul Muhammad, 2016 (in Kurdish, PDF)
