The 1,3-dipolar cycloaddition of the aryl azide and some its of derivatives with cinnamic
acid was studied theoretically using different methods of Density Functional Theory
(DFT): B3LYP, B3PW91, MPW1PBE, MPW1PW91 and M062X with the basic set 6-
3
1g(d). Most of the used levels of theories provide closed results qualitatively, and the
results of the level of theory M062X / 6-31g (d) show that these reactions in the gas state
carried out spontaneously to form several stable energy products; the products P1 and P2
are most stable, but all the reactions are very slow and one of the products P1 is more
spontaneous than P2 , but the formation reaction of P2 is faster.
On the other hand, when these reactions were studied with different solvents, it is found
that solvents to have no actual effects on the rates of these reactions.
The Diels - Alder reactions of furan and some derivatives with maleic anhydride
have been studied using methods of density functional theory (DFT): B3LYP, B3PW91,
MPW1PW91 and MPW1BPE with 6-31g(d) bases set and proceeding energy cor-relation
at M
P4 level of theory with same bases set. The results of this study showed that, for the
Diels - Alder reaction of Furan and 2-methyl furan with maleic anhydride, the reaction of
formation of exo-adduct proceeds under thermodynamical control, and the reaction of
formation of endo-adduct proceeds under kinatic control, but for the 2-furylmethanol, 2-
furylmethyl acetate and 2-furylmethyl benzoate, the reactions of formation of exo-adduct
proceed under thermodynamical and kinetic controls. The MPW1BPE/6-31g(d) level of
theory was advanced susceptible results by comparison with the reference experimental
data; exactly for furan-maleic anhydride Diels - Alder reaction.
In this research, we studied the quantum effect of the electronic
density change effect of some sodium( Nan) clusters properties,
electronic and spectral properties changes.We have been studied
using density functional theory: (DFT/B3LYP(6-311+G(2d))).
Density Functional Theory (DFT) is a computational method that
derives properties of The sodium clusters (neutral and positively)
based on a determination of the electron density of the clusters.
تم في هذا البحث دراسة تفاعل أكسيد البنزوفيورازان مع الأسيتون لتشكيل المركب2-متيل 1 , 4-ثنائي أكسيد الكينوكسالين باستخدام الحفز الضوئي من خلال اتباع منهجية علمية جديدة تعتمد على محاكاة التفاعل كوانتياً ومن ثم تطبيقه تجريبياً
In this work some of Uranium compounds have
been studied using B3LYB/SDDALL Basis set and electron
density theory (DFT), That is because of the high accuracy and
reliability for the results obtained.
We will first introduce the basic ingredient of Fourier methods in
section 1, then we will do some analysis on the Fourier
approximation, in the last section, we will apply the Fourier
method to solve some ODEs . we will write Matlab code for
num
erical result .
This work aims to analyze the performance of Orthogonal Frequency Division
Multiplexing (OFDM) applied in the fourth generation mobile networks and WiFi. Fuzzy
logic technique is used in this study to analyze the problem of OFDM, taking into
consi
deration the modulation techniques applied in OFDM. Three input parameters in the
fuzzy logic system are mainly considered: signal-to-noise ratio, the modulation degree and
the number of sub-carriers. The output parameters are selected to be the bandwidth and bit
error rate. This requires an analytical study to determine the optimal values of the input
parameters used in this study. This means studying the membership of functions of each
input and output parameter using fuzzy logic.
A common challenge in designing a wireless system is to overcome
the effects of the wireless channel, such as multi-path propagation,
and Inter-symbol Interference. and the ability of OFDM to combat
the effects of multi-path propagation made it th
e modulation of
choice for third and fourth generation networks.
In OFDM system we transmit data symbols on a large number of
subcarriers, and these data symbols exposed to changes in
amplitude and phase, caused of noise and frequency selective
fading and Doppler shift .
To get the transmitted data at the receiver we must cope with these
changes, so we need to know the channel response at every
subcarrier and every symbol, and for that reason we use PILOTS
and we use many methods to estimate the channel response depend
on pilots, and the most important channel is LMMSE Method.
We will discuss in these issue the wiener filtering method
(LMMSE) which give best performance but it is very complicated,
so we will use Discrete Fourier Transform (DFT) to reduce the
complexity of these method and we will study the BER and MSE in
both case when we use QPSK or 16QAM Modulation .
In this work, theoretical calculation of the ground and excited state of
coumarin compounds are performed using DFT-B3LYP and CIS methods with
6-31G basis set. IR spectrum, UV/Vis spectrum, molecular orbitals and energy
gap are calculated. We use
different solvents ethanol, methanol, water,
acetonitrile (ACN), dimethyl sulfoxide (DMSO), acetone, and dichloromethane
to compare values of UV/Vis absorption spectra. Then the calculated results are
compared with the experimental values.
Theoretical calculations using density functional theory (DFT) both on semi
empirical and Ab initio levels have been carried out for pyrromethene laser
dye and related compounds (PM-chromophore, PM-4m, PM 546, PM650 PM
567 and PM597). We carried o
ut theoretical calculations using DFT, AM1, TDDFT
and CIS on ground and excited states for the selected laser dye materials,
we obtained the optimized geometry of the molecules, UV, IR spectrum, and
the transition between the ground S0 and the first excited S1 states exclusively,
the HOMO and LUMO states and other properties.
