Research Journal of Aleppo University - جامعة حلب ... · Research Journal of Aleppo University ... Ibrahim Alo Co -doping ZnO Semiconductor Type -n ... Dr. Saleh El-Kadri

Research Journal

of

Aleppo University

Basic Science Series

A Periodical Issued by University of Aleppo

Vol. 76 - 2011

Published at: January/2016

ISSN 2227-9210

All rights reserved .No part of this publication may be

reproduced,stored in a retrieval system or transmitted in any

form without the prior written permission of the publisher .

Basic Science Series

Chairman of the Editorial

Prof. Dr. Kamal Khoudary Vice president for scientific research and high studies affairs

Editor in Chief Prof. Dr. Nawar Kadan

Editorial Board

Dr. Abdul Kader Hariri Dr. Ousama Dabbit Dr. Shahadeh Assadi

Dr. M. Karroum Dr. Abdul Moniem Ahmad Dr. Safwan Ashour

PRODUCTION Eng.Rama Mulki

The view expressed in this issue are those of the authors and do not necessarily

reflect the views of the Editorial Board or the Policies of the University of Aleppo

proof reading Aisha Moussa (Engish) Maissa Dada (Arabic)

5

Contents

Dr. M Anwar Batal

Dr. Ghassan Nashed

Ibrahim Alo

Co-doping ZnO Semiconductor Type-n

Converted To Type-p by USP Method 9

Dr. Farouk Kandil

Dr. Nadeem Almhna

Souad Kedy

Solvent Extraction of Ag+, Cu2+ and

Ni2+ Ions by Macrocycles with N6O4

or N4O8 Donors

23

Dr. H. Al Najjar

Dr. A. A. Shaar

M. EB. Al Muhammad

Improvement on AES Algorithm

(Rijndael) through Using Matrix

Inverse and EC Mathematics over

Finite Fields

33

Dr. M. Anowr Batal

Ghoson Mearawi

Photon Diffusion from Diode Source of

Wave Length 808nm in Biogical Tissue

and Using Matlab for Simulation

35

Dr. M.A. Batal

Dr. H. Kanagha

M. Barghos

Doping Effect of Zinc Oxide with

Phosphorus Oxide on Electrical and

Electronic Properties

37

Dr. Hamdo Al-Najar

Dr. Abdul Rahman Hussian

Zainab Shawa

Proposing Hybrid Algorithm in

Optimizing the Mathematical Models

Used in Metals Rolling

39

Dr .M. Matar

Dr. Salah Corini

Dr. M. Ismail

Lama Togus

A Field Survey of Sugar Beet Root Rot

Disease in Raqqa Province, Syria

41

Dr. Rehab Dabbas The Effect of Using Diatoms Related to

AL-Assad Lake's Water as Organic

Fertilization for the Plan Vicia faba

43

Dr. Kamal Khoudary

Dr. M. Zakaria Nassani

Rami Badleh

Preparation and Evaluation of Some

Dental Waxes That Can Be Used in

Prosthetic Dentistry

45

Dr. Ghassan Nashed

Dr. M.A. Batal

Fares Haj Jneed

Sensing of Tin Oxide Thin Films Doped

in Iron Oxide toward H2S & H2 Gases

47

Dr. O. Dabbit

M. N. Mahayri

Purification and Treatment of Syrian

Natural Zeolite by Quaternary

Ammonium Salts and Studying Its

Surface Properties

49

Dr. Jallal Soda

Dr. A. Nadim Akkad

Effect of the Presence of the Polymer

Layers on the Mechanic Properties of

Steel

51

6

Dr. Tarek Zarouri

Dr. M. Hamzh

Zulfikar Mahmoud

Study of Some Optical Properties of

Thin Films Deposited by Chemical

Solution Method CSD

53

Dr. Saleh El-Kadri

Dr. A. Al-Shaghel

Fadi Al-Rouh

Study of Enzymatic Esterification for

Cottonseed Oil by GC-MS Technique

55

Dr. M. Nasouh Alaya

Dr. Fatema El-Sejarieh

Abeer Amin

Determination of the Adsorption

Properties and Chemistry of H3PO4-

Activad Carbon Obtained from Wild

Cherry Stones and Removal of Some

Dyes from Aqueous Solutions

57

Dr. A.Talleb

Dr. F. Bador

Dr. A .Salah

F. Salh

Calibration of High Energy Photon

Beams for Medical Linear Accelerator

in Damascus Medical Hospital

(Damascus) Using Cylindrical Ion

Chambers in Water Phantom

59

Dr. Zakria Nout

Dr. Moa’Az Abdelmajeed

Manal Swid

Study of Solution of Boundary-Value

Problem on a Geometric Graph with

Generalized Kirchhoff Condition

61

Dr. Nazeeh Kutaish

Dr. Said Abdel Nour

M. Alkhdear

Effect of Sodium Dodecyl Sulfate on

Hydrodynamic and Structural

Properties of Polyacrylonitrile

63

Dr. Nader Elnader

Dr. Samir Saad

Ali Khallawy

Results on Graded Ring by Orthogonal

Band and by Completely Regular

Semigroup Whose Maximal Subgroups

are Polycyclic-by-Finite Group

65

Dr. Sabah Blaj A Comparative Study of the

Competence Used in Some

Immuonotests for the Diagnosis of

Toxoplasmosis

67

Dr. Hasan Hammadi

Dr. Mazen Kabbani

Shaza Issa

Isolation of Some Microbial Species

Causing Infections of the Tissues

Supporting the Teeth and Study of

Their Sensitivity to Antibiotics

69

Dr. M. Saleh Himmami

Dr. Triq Zarori

M. Halabi

Studying the Building and Mechanical

Features of the Metal Mixtures from:

(AL1-x-yMgxCuy) and(Al1-xMgx)

Brought by Pressure

71

Dr. Nael Yasri

Dr. Hassan Seddik

A. Halabi

Lead Determination by Applying

Electrochemical Method Using

PEDOT: PSS Carbon Modified

Electrode Sensor

73

7

Dr. Bachir Kharrat

Dr. Ali Hinnawi

Hussam Al-Din Alawa

Study on Boundary Value Problem of

Functionally Graded Sandwich Plate

under Effect of Mechanical and

Thermal Loads

75

Dr. Mounir Al Hamed

Dr. Malek Ali

Giath Marate

Optical Response for WO3 Thin Film

Used as Smart Windows

77

Dr. Abdallah Taleb Study of Stability of Optical Response

in the FXG Gel Dosimeter

79

Dr. Abdullah Jhar

Dr. Mahmud Kashtari

Alisar Abdel- Latief

The Use of Microorganisms to Produce

Biofuel (Bioethanol) from the Corn

Cobs

81

Res. J. of Aleppo Univ. Basic Sciences Series No. 76 2011

8

Co-doping ZnO Semiconductor Type-n Converted To

Type-p by USP Method M Anwar Batal, Ghassan Nashed, Ibrahim Alo

*

Dept. of Physics, Faculty of Science, University of Aleppo

*Postgraduate Student (MSc.)*

Abstract

Ultrasonic spray pyrolysis (USP) method was used to deposit

ZnO thin films co-doped with (N,P) on glass substrate. The influence

of substrate temperature and annealing temperature on transmittance

spectrum and quality of deposited films was investigated. The results

show that the film deposited at high substrate temperature about 400C0

gives films that are converted to P-type semiconductor, and the films

deposited show a nanostructure. Electrical (DC- AC) measurements

were done. Some electrical parameters of ZnO films co-doped with (N,

P) were determined.

Introduction Since the invention of the first semiconductor transistor in 1947

by the scientists of Bell Labs, the semiconductor industry has grown at

an incredible pace, fabricating faster, smaller, and more powerful

devices. Zinc oxide is a semiconductor material with many promising

properties for blue/UV optoelectronics, transparent electronics,

spintronic devices and sensor applications. It has been commonly used

in many industrial manufacturing processes including paints,

cosmetics, pharmaceuticals, plastics, batteries, electrical equipment,

rubber, soap, and textiles. To realize such optoelectronic devices, it is

required to control the electronic properties, such as the nature of

conduction, as well as its carrier density and mobility. Zno has direct

bandgap energy of 3.37 eV, which makes it transparent in a visible

light and operates in the UV to blue wavelengths. ZnO has a hexagonal

wurtzite crystal structure with lattice parameters a=3.25Å and c=5.12

Å. The Zn atoms are tetrahedrally coordinated with four O atoms [1,6].

ZnO probably has the richest family of nanostructures among

all materials, both in structures and in properties, and this is a benefit

not only for understanding the fundamental phenomena in low-

dimensional systems, but also for developing new generation nano

devices with high performance.

Received 23/122010

Accepted 10/4/2011

Dr. Batal Dr. Nashed & Alo

01

ZnO is a key technological material, which has a diverse group of

growth morphologies, such as nanobelts, nanowires, nanocages,

nanocombs, nanosprings, nanorings and nanohelixes. These

nanostructures could have novel applications in optoelectronics,

sensors, transducers and biomedical sciences [1].

Issue ZnO, almost exclusively, occurs naturally as n-type. The main

issue currently limiting the production of ZnO-based devices is that

achievement of p-type ZnO. But there is a difficulty in achieving p-

type material [2]. For p-type conductivity in ZnO, elements such as Al,

Ga, and In on the Zn sites and Cl and I on the O sites can potentially

form shallow donors in ZnO, and so are elements such as Li, Na, K,

Cu, and Ag on the Zn sites and N, P, Sb, and As on the O sites form

acceptors, albeit deep, in ZnO [6]. The attention is now once again

focused back onto N, which was originally thought to be the most

promising p-type doping candidate due to its close ionic radius to O

[3,4]. The difficulties may arise from a variety of causes. Attempted p-

type dopants may be compensated by low-energy native defects, such

as Zni or V0 [5], or background impurities (H) with propensity to n-

type doping. Some centers of compensation are pinned to the same

level that hardly depends on the position of valences and conductive

bands. This compensation problem is the most challenging

phenomenon in wide-gap semiconductors and ZnO, in particular. Low

solubility of the dopant in the host material and precipitate formation

are also possible causes. The deep impurity level can also be a source

of the doping problem, causing significant resistance to the formation

of shallow acceptor level. Nitrogen has the smallest ionic radius (1.68

A0), which is very close to O ionic radius of 1.38 A

0. Although

nitrogen has been considered as the best candidate for p-type doping

for ZnO, the point should be remade. The solubility of N in ZnO is low

and it introduces a relatively deep acceptor level. Therefore, it is

necessary to find methods which can enhance the solubility of N in

ZnO and lower the acceptor ionization energy. For this purpose,

acceptor –acceptor co-doping method has been proposed to realize

highly conducting p-type ZnO thin films nanostructures[6].

Experimental Details Series of N–P co-doped ZnO films were prepared by USP

deposition method. The simple experimental set up of Ultrasonic Spray

Pyrolysis method can be seen in Fig. 1


00

Aqueous solution (Zn(NO3)2·4H2O),(P2O5) were chosen as the

sources of zinc, nitrogen and phosphorus, respectively.

Fig. 1. Experimental setup of Ultrasonic Spray Pyrolysis method (1. Carrier gas

pipe, 2. Container, 3. Solution, 4. Ultrasonic nebulizer, 5. Heating system,

6.Nozzle, 7. Deposition room, 8. Substrate, and 9. Heating Controller).

Substrate was microscope slides which were cleaned and

washed by aceton and de-ionized water, then dried by nitrogen gas. In

order to obtain p-type ZnO thin films, different weight ratios of

Zn(NO3)24H2O :P2O5(Merck) were prepared. The aerosol of precursor

solution was generated by commercial ultrasonic nebulizer working at

frequency 2.5 MHz(BREMED- BD5200). The generated aerosol was

carried by nitrogen gas to substrate which can be heated to different

temperatures up to 500 °C.A spectrophotometer type (JASCO UV-

VIS600) used to measure absorption and transmission spectrum.AC

and DC measurements were taken by analyzer Gain phase

(Schlumberger SI 1253) and high resistance meter (hp 4339A).

Results and Discussion N–P dual-acceptor-doped ZnO (ZnO:(N, P)) thin films were

deposited on microscope slides by ultrasonic spray pyrolysis. In this

technique, a mist of a solution containing the precursor materials is

ultrasonically generated and sprayed through a spraying nozzle over a

substrate which was previously heated to the desired temperature

which has a dominant role in producing thin films which have specific

properties. The distance between nozzle and substrate was kept at one

cm. The spraying solution consisted of different weight rate of zinc

nitrate (Zn(NO3)2·4H2O) and of Phosphorus pentoxide (P2O5) which

was solved in deionized water. A few drops of hydrochloric acid were

added to prevent any precipitation. The carrier gas was nitrogen with a

flow of 1 l/min. The substrate temperature was varied during the

deposition. The films were deposited for 20 min at atmospheric


01

pressure. The obtained samples were annealed for 30 min at a

temperature 6000C.

Spectroscopy Measurements

1-Study of electronic properties with varying weight ratio:

To study the effect of varying weight ratio of precursor

materials on the optical properties which affect the electronic

properties of thin films, absorption and transmission spectra in the rang

(300-900)nm wavelength were measured for different samples of thin

films. Table (1) shows different parameters of prepared samples.

fig(2): Absorption spectrum of ZnO(N,P) at Temperature of 400 C

O and Weight

ratio of [Zn(NO3)2.4H2O(9.7gr), P2O5 (0.3gr)]


02

fig(3): Absorption spectrum of ZnO(N,P) at Temperature of 400 CO

and Weight



O and Weight



O and Weight


Table(1): shows different parameters of prepared samples

T=400C0

Specimen 1 2 3 4

Weight ratio of

Zn(NO3)2.4H2O 9.2(gr) 9.5(gr) 9.7(gr) 9.9(gr)

Weight ratio of P2O5 0.8(gr) 0.5(gr) 0.3(gr) 0.1(gr)

From the absorption spectrums figures (2,3,4,5), we note that

all samples have the same absorption peaks at wavelength (370nm).

So, we can say that changing the weight ratios does not influence the

direct band gab energy. We can also note the absorption spectrum of

the samples that have different slopes, varying with increasing weight

ratio of Zn(NO3)2.4H2O. It is evident that wherever the nitrogen ratio

increases, it will form multi acceptors levels, and the nitrogen dopants


03

form many acceptors levels in the energy gap of ZnO . From the above

figures, we can see many peaks at different wave lengths (i.e.720nm).

These peaks related to deep levels were present in energy band gap and

vacancies of Zn or defects of oxygen as Vo [7].

2- Study of Electronic Properties with Varying Substrate

Temperature To study the influence of substrate temperature on the

electronic properties of thin films, absorption and transmission spectra

in the rang (300-900)nm wavelength were measured for different

samples of thin films. Table (2) shows different parameters of prepared

samples. Table ( 2) shows different parameters of prepared samples.

Weight ratio of [Zn(NO3)2.4H2O(9.7gr), P2O5 (0.3gr)]

specimen 5 6 7 8

Substrate temperature 300 C0 350 C

0 400 C

0 450 C

0

Absorption edge 320nm 330nm 372nm 367nm

Eg(ev) 3.87 3.75 3.33 3.37

Figures (6,7,8,9) show the absorption spectrum of ZnO films deposited

at various substrate temperatures. We note that the absorption edge

shifted to shorter wavelength as the temperature is decreased, so that

the optical band gap blueshifted from 3.33 to 3.87 eV, and we can say

that the optical band gap decreased, and the optimal substrate

temperature is 400 C0 which gives the smallest ZnO optical band gap.

So, we can expect that at about 400 C0, ZnO is converted from n-type

to p- type, and at temperature up to 450 C0, ZnO is back to n- type and

that will be confirmed later at the electrical study.

Fig(6): Absorption spectrum of ZnO(N,P) at Temperature of 300 C

0 and Weight



04


0 and Weight


Fig(8): Absorption spectrum of ZnO(N,P) at Temperature of 400 C

0and Weight


Fig(9):Absorption spectrum of ZnO(N,P) at Temperature of 450 C0 and Weight


The Effect of Substrate Temperature and Solution Concentration

on the ZnO Grains Size

To study the effect of deposition temperature,

[Zn(NO3)2.4H2O(9.7gr), P2O5 (0.3gr)] were solved in 100ml of ionized

water. The surface morphology was examined by Atomic Force

scanning (AFM).


05

Fig (10a): The AFM micrograph of the film deposited at 300 °C

Fig(10b): The AFM micrograph of the film deposited at 400 °C

fig(10c): The AFM micrograph of the film deposited at 450 °C


06

Fig(10d): The AFM micrograph of the film deposited at 300 °C with low

concentration

The AFM micrograph of the film deposited at 300 °C is

presented in Fig. 10a. The film consists of grains with a size about

137nm. The AFM micrograph, fig.10b, shows that the film deposited

at 400 °C is no more dense and consists of grains with a diameter of

230nm. When the temperature increases to 450°C, the AFM

micrograph, fig.10c, shows that the grains have a diameter of 537nm.

Thus, deposition at higher temperatures increases the size of the rods

and leads to lower substrate coverage. When concentration of the

solution is lowered, [Zn(NO3)2.4H2O(9.7gr), P2O5 (0.3gr)] were solved

in 1000ml of ionized water at the temperature 300 C0. The AFM

micrograph, fig.10d, shows that the diameter of grains decreased and

became 125nm, so the lower concentration is better than the high

concentration to obtain ZnO nanostructure. The results of the AFM

study are summarized in Table 3. Table (3) shows the effect of substrate temperature and concentration of

solution on the size of ZnO grains.

Solution solved in

100ml of ionized water

Temperature 300 C0 400 C

0 450 C

0

Diameter 137nm 230nm 537nm

Solution solved in 1000 ml

of ionized water

Temperature 300 C0

Diameter 125nm

Electrical Properties AC measurement carried out using GAIN PHASE

ANALYZER (SI1253), a complex impedance spectrum in frequency

rang (0.001- 20000HZ), was taken for the film (deposited at 400 C0).

The measurements were taken at different temperatures. The

impedance is given by [10]:

Z=R(W)+J X(W) (1)


07

Where R(w) the real part, and X(W) the imaginary part of the

impedance. The relationship between X(W) and R(W) was carried out

in frequency rang (1- 20 KHZ). The figures (11,12,13,14) showed that

they have a semicircle shape and this represents of Debay schematic[8]

.

Fig(11):temperature of sample is 30 C

0

Fig(12):temperature of sample is 75 C0

Fig(13):Temperature of sample is 100 C0

Fig(14):temperature of sample is 125 C0

Whereas the schematics (X(W), R(W)) are represented by

Debay mode. One can conclude that the shape of grains (nanorods) in


08

the film is homogeneous, and this means that the equivalent circuit

between two nano-grains is resistant in parallel with capacitance. This

agrees with the results which were found when we used AFM

measurements. The other parameters were found when the frequency

was varying with temperature. From the relationship F=F0 e KT

Ea- (2),

the relationship between (ln(F)and 1/T) was drawn and from its slope,

the activation energy was found to be Ea= 0.0145ev. where the values

of frequency were taken when X(w)=R(w). Table(4) shows values of frequency at X(w)=R(w) as a function to temperature

T(k ) 1/T(1/k ) F(HZ) ln(F) 303 0.0033 210 5.347108 348 0.002874 225 5.4161 373 0.002681 235 5.459586 398 0.002513 240 5.480639

Fig(15) represents the relationship between ln(F) as a function to 1/T

The majority carrier concentration was calculated at home

temperature (300k ) from the relationship,

N=N0 e KT

Ea- (3), whereN0=ρv 4.347E+19cm

-3, ρ=5.6gr/cm

3,

Na=6,02E26,K=1.38E23J/k , and found that N=2.48E+19cm-3

.

DC measurements were carried out using high resistance meter

(hp4339A). The resistance was measured in temperature rang (300-

375k) and at constant voltage (V=200volt). Table (5) shows the values of resistance as a function of temperature at a

constant voltage (V=200v).

V=200 volt

T(k) I(A) R(Ω) (1/T)k-1

Ln (R)

333 1.98E-06 1.01E+08 0.003003 18.43073

353 2.80E-06 7.14E+07 0.002833 18.08421

363 3.10E-06 6.45E+07 0.002755 17.98243


11

From the relationship R=R0 e K T

Φ

(4), by drawing the

relationship between ln(R) and inverse temperature (1/T) and from its

slope, Schockly barrier height is found to be Ф=0.159ev

Fig(16) represents the relationship between ln(R) as a function to 1/T at

constant voltage(V=200v).

To determine the type of majority carrier, we use the relationship,

(02Cp

1

Cp

1 )

2 =

r 0 D A

2

qε ε (N N ) ( VΦ ) (5)

Where Cp and Cp0 are the grain boundary capacitance per unit of area

biased, respectively with V and zero volts, εr the dielectric constant (εr

to ZnO grain is 8.5) ε0 the permittivity of free space = 8.85E-12

F/M, q=1.6E-19 coul (electron charge)[8,9].

Where Cpo=Cp(V) 0V =2

1[

2

εqε N 0r]

2

1

and parallel capacitance is[10]: Cp=

]2

1)[(2

1

)()(

)(

wX

wRwfX

The measured values of ( 0

1 1

Cp 2Cp)2 as a function of V at a constant

frequency F=20KHZ.


10

Fig(17) represents the relationship between 1/Cp^2 and V at F=20KHZ

From its slope ND -NA=N= - 2.769E+11cm-3

.

Conclusion NA >> ND and the type of majority carriers is p-type.

References [1]. JAGADISH C.; PEARTON S., 2006- (Editors), Zinc Oxide Bulk,

Thin Films and Nanostructures, Elsevier Limited

[2]. CHIN-CHING L.; SAN-YUAN C.; SYH-YUH C.; 2004- Physical

characteristics and photoluminescence properties of phosphorous-

implanted ZnO thin films, Applied Surface Science 238, 405–409

[3]. ZENG Y.J.; YE Z.Z.; XU W.Z.; LIU B.; CHE Y.; ZHU L.P.,

ZHAO B.H., 2007- Study on the Hall-effect and

photoluminescence of N-doped p-type ZnO thin films, Materials

Letters, 61, 41–44

[4]. RUIQIN D.; HUIQUN Z.; YI W, 2008- Realization of phosphorus-

doped p-type ZnO thin films via diffusion and thermal activation,

Materials Letters 62, 498–500

[5]. WALUKIEWICZ W., 1994- Defect formation and diffusion in

heavily doped semiconductors. Physical Review B:Condensed

Matter, 50, 5221.

[6]. HADIS M.; AND ÜMIT Ö.; ZINC O., 2009- Fundamentals,

Materials and Device Technology, WILEY-VCH Verlag GmbH &

Co. KGaA, Weinheim.

[7]. KRUNKS M.; DEDOVA T.; OJA AÇIK I., 2006- Spray pyrolysis

deposition of zinc oxide nanostructured layers, Thin Solid Films,

515 1157–1160

[8]. PAULO R.B.; JOSÉ A.V.; ELSON L., 2007- Admittance and

dielectric spectroscopy of polycrystalline semiconductors, Journal

of the European Ceramic Society, 27, 4313–4320

[9]. FERNAŃDEZ-HEVIA D.; DE FRUTOS J.; CABALLERO A.C.;

FERNAŃDEZ J.F., 2002- Mott–Schottky behavior of strongly

pinned double Schottky barriers and characterization of ceramic


11

varistors, JOURNAL OF APPLIED PHYSICS VOLUME 92,

NUMBER 5 1 SEPTEMBER.

[10]. ALBDULLAH K.; BUI A.; LOUBIERE A., 1991- Low

frequency and low temperature behavior of ZnO –based varistor by

AC impedance measurements J. Appl. Phys. 69,4046-4052 [11]. KLEIN A.; RECH B.; ELLMER K., 2008- Transparent

Conductive Zinc Oxide :Basics and Applications in Thin Film

Solar cells, Springer 259-261

Res. J. of Aleppo Univ. Basic Science Series No. 76 2011

32

Solvent Extraction of Ag+, Cu

2+ and Ni

2+ Ions by

Macrocycles with N6O4 or N4O8 Donors

Farouk Kandil, Nadeem Almhna, Souad Kedy* Dept. of Chemistry, Faculty of Science, University of Damascus

*Postgraduate Student (PhD)

Abstract

Two new macrocyclic Schiff bases (II) and (III) containing

nitrogen-oxygen donor atoms were designed and synthesized by

reaction between diethylene triamine or 2,2΄- (ethylenedioxy) bis

(ethylamine) and the intermediate compound 1,4- bis(2-formylphenyl)-

1,4- dioxabutane (I). Identification of these macrocyclic Schiff bases:

8, 11, 14, 25, 28, 31- hexaaza- 5,6; 16,17; 22, 23; 33, 34- tetraphenyl

-1,4,18,21-tetraoxacyclotetratricozane-7, 14, 24, 31-tetraene. (II) and

8, 17, 28 37- tetraaza- 5, 6; 19, 20; 25, 26; 39, 40-tetraphenyl 1, 4, 11,

14, 21, 24, 31, 34 -octaoxacyclo-tetracontan-7, 17, 27,37-tetraene. (III)

was determined by (LC-MS), (IR) and (1H-NMR) spectroscopy. The

liquid- liquid extraction of metal picrates such as Ag+, Cu

2+ and Ni

2+

from Aqueous phase to organic phase was carried out using the novel

ligands. The effect of chloroform and dichloromethane as organic

solvents over the metal picrate extractions was investigated at 25±

0.1oC by using atomic absorption spectrometer.

1. Introduction Polyaza macrocycles with large cavities have received recent

interests as inorganic cation receptors. The cyclic arrangement of a

large number of donor atoms and the flexibility of these ligands make

them good hosts for ion complexes [1], which are also used as

spectrophotometric analytical reagents. For example, metal ion with

enormous ion is important in many biological processes. In particular,

heavy metal ions are effective enzyme inhibitors exerting toxic effects

on living system [2]. Therefore, separation and determination of toxic

metal ion such as mercury, lead, and cadmium in environmental

Key words: macrocyclic Schiff bases, liquid- liquid extraction.

Received 27/12/2001

Accepted 20/4/2001

Dr. Kandil Dr. Almhna & Kedy

32

sources play an important role for healthy life. Although the

macrocyclic compounds are mainly the oxygen, sulfur, and nitrogen

types, the macrocyclic compounds used in solvent extraction were

mostly of the oxygen type [3]. A number of methods for the

preparation of the large polyaza macrocyclic have been reported. The

most common synthetic procedure requires the use of N- tosyl groups

to protect and activate the nitrogen atoms in the cyclization step [4].

Ring closure occurs by a condensation reaction of N-tosylated

polyamines with the appropriate ditosylate ester or dihalide in DMF in

the presence of base [5]. These reactions allow the production of

polyaza macrocycles in moderate yields [6], but removing the N- tosyl

groups requires drastic conditions and is not always straightforward.

Another cyclization process uses the template ring closure formation of

cyclic di- or tetra Schiff Base. This is a simple process, but it is often

difficult to choose the correct template metal ion or to predict certain

ring contraction reaction where the template cation does not coordinate

with all of the ring nitrogen atoms [7]. In some cases, reduction of the

cyclic Schiff Base and removal of the template ion have been difficult

[8]. Anon template method for the formation of macrocyclic poly

Schiff bases has been studied. This procedure often gives a polymeric

material after cyclization reaction, while there is no need to remove a

metal ion [9]. In the present work, we used A non template method for

the formation of two novel macrocyclic Schiff bases: (II) and (III),

then they were used for the transfer of various metal ions from the

aqueous phases into the organic phases in liquid–liquid extraction

systems.

CH N NH

N CH

OO

O O

HCNCHHNN


32

(II)

CH N N CH

OO

O O

HCNO

O O

CH

N O

(III)

2. Experiment 2.1. Materials and Method

Chloroform, dimethyformamide, methanol, K2CO3, Cu(NO3)2.

3H2O, Ag(NO3), Ni(NO3)2.6H2O, and picric acid were the analytical

grade reagents and were purchased from Merck. Diethylene triamine,

2,2΄- (ethylenedioxy) bis(ethylamine), salicyl aldehyde and

dibromoethane were obtained from sigma- Aldrich. IR spectra were

obtained on Jusco 300 FT-IR Spectrometer with the samples in

compressed KBr discs. Mass spectra of the ligand were measured on a

micro mass Quattro LC-MS/MS Spectrometer. 1

H- NMR spectra were

recorded at ambient Broker DT-400 Spectrometer using CDCl3 with

DMSO- DMF as the internal standard. A Hitachi Model 180-80

Atomic absorptions Spectrometer (acetylene/air flame) was used to

determine the concentration of metal ions.

2.2. Synthesis of: 1,4- bis(2-formylphenyl)-1,4- dioxabutane(I)

CHO

O O

OHC

CHO

OH

2+

Br Br

+ K2CO3

(I) To a stirred solution of salicyl aldehyde (2.44 g, 0.02mol) and

K2CO3 (1.38g, 0.01mol) in DMF (50ml), dibromoethane (1.88 g, 0.01mol) in DMF(10ml) was added drop-wise. The reaction was

continued for 10h at 150-155oC and then 5h at room temperature [10].


32

After the addition was completed, 20ml distilled water was added and

it was kept in a refrigerator. 1h later the precipitate was filtered,

washed by 50ml water, dried in air, and re-crystallized from ethanol.

Yield: 2.16 g (80%), color: bright brown, Rf:0.6 (petroleumether:

ethylacetate) (2:1)

m.p: 120–122oC, (LS- MS): m/z = 270, IR (KBr pellets, cm

−1): 3100

(aromatic–CH), 2920–2847 (Aliphatic -C-H), 1710 (C=O)str, 1488-

1460 (aromatic C=C), 1287,1238(Ar-O), 1150, 1100(R-O),

757(substituted benzene).

2.3. Synthesis of: 8,11,14,25,28,31- hexaaza- 5,6; 16,17;22,23;

33,34- tetraphenyl- 1,4,18,21-tetraoxa cyclotetratricozane-7,14,24,31-

tetraene (II)

The macrocyclic (II) was prepared by the drop-wise addition of

solution of the diethylenetriamine (0.206g ، 2mmol) in methanol

(40ml) to a stirred solution of compound (I) (0.81g ، 2mmol) in

methanol (60ml). After the addition was completed, the stirring was

continued for 15h; a solid product began to separate from the solution

and it was purified from ethanol.

Color: bright yellow solid.

Yield: 1.01 g (74%); Rf:0.8 (Chloroform), m.p = 52-55oC, (LS- MS):

m/z =674. IR (KBr pellets, cm−1

): 3220 (–N-H), 3180 (aromatic–CH),

2880–2774 (Aliphatic -C-H), 1645 (CH=N)str, 1480-1460 (aromatic

C=C), 1267,1238(aromatic -O), 1170,1140(R-O),753 (substituted

benzene). 1H-NMR (DMSO-d6): 8.42 (s, CH=N), 7.30-8.21 (m, Ar–

H), 4.50 (t,-CH2-O), 3.92(t,CH2-O- ph), 3.62 -3.78(t, CH2 -N -),

2.8 2 (t, CH2-NH -), 2.22 (m, -NH -).

2.4. Synthesis of: 8,17,28,37- tetra aza-5,6; 19,20 ;25,26 ;39,40-

tetraphenyl 1,4,11, 14,21,24,31,34– octaoxacyclo tetracontan-

7,17,27,37- tetraene. (III)

The macrocyclic (III) was prepared by the drop-wise addition

of solution of the 2,2΄- ethylenedioxy bis(ethylamine) (0.74 g ، 5

mmol) in methanol (80 ml) to a stirred solution of compound (I) (1.35

g ، 5 mmol) in methanol(90ml). After the addition was completed, the

stirring was continued for 20h, a solid product began to separate from

solution. It was purified by washing with ethanol. Color: bright brown

m.p< 230oC with decomposition, Yield: 2.3g (60%), Rf:0.7

(Chloroform). (LS- MS): m/z =764; IR (KBr pellets, cm−1

): 3037

(aromatic–CH), 2888–2847 (Aliphatic -C-H), 1670 (CH=N)str, 1488-

1460 (aromatic C=C), 1287,1238 (aromatic -O), 1090,1130(R-O),754


32

(substituted benzene). 1

H-NMR (DMSO-d6): 8.55 (s, CH=N), 7.33 -

7.54 (m, Ar–H), 4.30 (t, -CH2-O), 3.52(t, CH2-O-ph), 3.7 -3.8

(t, CH2-N=).

3. Solvent Extraction Transition metal picrates were prepared by the step-wise

addition of a 1×10-2

M of metal nitrate solution to a 1.25×10-4

M

aqueous picric acid solution and shaking at 25 oC for 1h. An organic

solution (5ml) of ligand (1.25×10-5

M) and an aqueous solution (5ml)

containing metal picrate (1.25×10-4

M) were shaken for 1h. The

resulting mixture was allowed to stand for at least 1h in order to

complete the phase separation. The aqueous phase was separated and

the concentration of cation in aqueous phase was determined by atomic

absorption spectrometer.

The extractability was calculated from Equation (1)

% E = [(A0-A)/A0] × 100 (1)

Where A0 is the concentration of cation in aqueous phase before

extraction. A is the concentration of cation in aqueous phase after

extraction. The dependence of the distribution ratio (D) of the cation

between the aqueous phase and the organic phase upon the ligand

concentration was examined. The range of ligand concentration was

from 1×10-5

M to 1. 5×10-4

M .

The general extraction equilibrium is assumed to be given by

Equation (2).

Mn+

aq + npic -aq + m Lorg =[ M(Pic)n(L)m]org (2)

The following logarithmic expression is valid for the above extraction

system.

LogD= n log[Pic] + log Kex + m log [L] (3)

The extraction equilibrium constant (log Kex) between an

aqueous solution of metal picrates and an organic solution of Schiff

base – cation complex can be calculated from Equation (3).

4. Result and Discussion 4.1. Macrocyclic Schiff Bases

In this work, we have found that in the reaction between

diethylene triamine and dialdehydes, the (2: 2) Schiff base macrocycle

is formed as the major product. The macrocyclic ligands were

characterized by mass spectrometry, IR, and 1H NMR spectroscopy.

The mass spectra of (II), and (III) play an important role in conforming

the (2:2) (dialdehydes:diamine). Macrocyclic Schiff 8,11,14,25,28,31-

hexaaza-5,6;16,17;22,23;33,34-tetraphenyl-1,4,18,21-


32

tetraoxcyclotetratricozane - 7,14,24,31- tetraene (II) was synthesized

by reaction of 1,4- bis(2-formylphenyl)-1,4- dioxabutane (I) with

diethylenetriamine in methanol under high dilution. The IR spectrum

of the ligand (II) shows a ν (CH=N)str peak 1645 cm−1

and the absence

of a ν(C= O) peak at around 1710 cm−1

indicated the condensation of

Schiff base. The mass spectra show a molecular peak at m/z = 270 for

(I) and m/z =674 for (II) which confirmed the formation of

macrocyclic Schiff Base (II). The NMR spectrum of the ligand (II)

exhibits aromatic protons between 7.30–8.21 ppm, and imine protons

at 8.42 ppm, with no signals corresponding to the formyl or amine

protons. Macrocyclic Schiff base 8,17,28,37-tetraaza-

5,6;19,20;25,26;39,40-tetraphenyl-1,4,11,14,21, 24,31,34–

octaoxacyclo-tetracontan-7,17,27,37-tetraene.(III) was synthesized by

reaction of 1,4-bis(2-formylphenyl)-1,4-dioxabutane(I) with 2,2΄-

ethylenedioxybis(ethylamine) in methanol under high dilution. The IR

spectrum of ligand (III) shows a ν (CH=N)str peak at 1670 cm−1

and the

absence of a ν(C= O) peak around 1710 cm−1

indicated the

condensation of Schiff base [11]. The mass spectra show a molecular

peak at m/z = 270 for (I) and m/z= 764 for (III) which confirmed the

formation of macrocyclic Schiff base (III). The NMR spectrum of the

ligand (III) exhibits aromatic protons between 7.33–7.54 ppm, and

imine protons at 8.55 ppm, with no signals corresponding to the formyl

or amine protons.

4.2. Extraction of Metal Picrates

Table (1) shows the extractability of Ag+, Cu

2+ and Ni

2+

picrates from the aqueous phase into organic phase by macrocyclic

Schiff bases (II) and (III). It is clear that the extractability results of the

macrocyclic Schiff bases are different for both organic solvents. When

chloroform was used as organic solvent, macrocyclic (II) extracted Ag+

ion 53.4%, but the other metal ions were not extracted effectively.

Macrocyclic (III) extracted Ag+ ion 76.3% for the same solvent. When

dichloromethane was used as organic solvent, macrocyclic (II)

extracted Ag+ ion 62.2%, while other metal ions were not extracted

effectively. Macrocyclic (III) extracted Ag+ ion 88.2% for the same

solvent. It is interesting to see that the percentage of the extraction of

the metal ions with macrocyclic (III) is higher than that of macrocyclic

(II). These results suggested that the phenyl group is the efficient

group in the extraction, and that increasing the number of oxygen

donor increases the percentage of the extraction of the metal ions. It

can be seen from table (1) that the solvent has an important effect upon


32

the cation extractability. These results may depend on the dielectric

constant of the solvents. The dielectric constants of dichloromethane

and chloroform are 9.1 and 4.8, respectively. Dichloromethane with a

higher dielectric constant is favorable for extracting all the metal ions,

and these results go online with the literature [12]. On the other hand,

better solvation of the complexes by dichloromethane may be a

valuable reason for better extraction. From the extraction data shown

in Table (1), it is clear that the ligands which have N6O4 and N4O8

donors showing in a general extractability for Ag + reach upto76.3%

and 88.2% respectively. These results show that both cations cavity

size and the type of binding sites in the ring contribute to the ability of

Ag + ion binding.

Table (1) the extractability of aqueous metal picrates for macrocyclic Schiff

bases (II) and (III) into organic phase.

Metal Ion Extractability a,c

% Extractability a,b

%

L (II) (III) (II) (III)

Ag + 53.4± 0.3 62.2± 0.3 76.3 ± 0.3 88.2± 0.1

Cu2+

25.3± 0.7 24.4± 0.4 33. 2± 0.2 39.1± 0.3

Ni2 13.2± 0.5 23.5± 0.5 22± 0.3 27.0± 0.3

atemperature: 25.0 ± 0.1

0C aqueous phase (5ml); [pic] =1.25×10

-5M,

organic phase(5ml)[L] =1.25×10-4

M bdefined as percent extracted in to dichloromethane phase

Cdefined as percent extracted in to chloroform phase

Table (2) shows the selectivity of silver picrate over the other

metal picrate for macrocyclic Schiff bases (II) and (III). The selectivity

indicated as DAg+ / Dmn+

. DAg+ and Dmn+

denotes the distribution ratio of

Ag+ ion and M

n+ ions, respectively. Macrocyclic Schiff bases (II) and

(III) indicated high selective extraction of Ag+ ion over the Cu

2+ and

Ni2+

ions with 80.2 and 79.1, respectively. The selectivity results for

dichloromethane are higher than those for chloroform. Table (2) the selectivity of silver picrate over the other metal picrates for

macrocyclic Schiff bases (II) and (III).

Metal Ion Selectivity a,c

DAg+ / Dmn+

Selectivity a,b

DAg+ / Dmn+

L (II) (III) (II) (III)

DAg+ / Dmn+

. 71.1± 0.3 73.8± 0. 4 80.2± 0.7 79.1± 0.3 bCalculated for dichloromethane as organic solvent phase

cCalculated for chloroform as organic solvent phase

Table (3) shows the relationship between the complex composition and

ionic diameter for the macrocyclic- cation. Schiff base (III) gave the

(1:1) (L:M) complex for Cu2+

and (1: 2) (L:M) complex for Ag+.


21

Table (3) The relationship between the composition extraction constant and

ionic diameter for the cation- macrocyclic Schiff base(III) complex.

Ionic diameter(A0) Complex composition(L:M) Metal ion

2.51 1: 2 Ag +

1.64 1: 1 Cu2+

Figure 1 shows that the relationship between the log D as a

function of log [L] should give a straight line with a slope of m, and

log Kex can be calculated from the intercept by using Equation (3). The

results of the experiments at the different concentration of macrocyclic

Schiff base (III) gave the composition of extracted Ag + - complex

which was(1:2) (L:M) and Cu2+

complex which was(1:1) (L:M) for the

ligand (III).

0

1

2

3

4

5

0 0.0002 0.0004 0.0006

log

D

logL

Fig. 1. Log D versus Log L for the extraction of Ag- picrate( ) and Cu-

picrate()

5. Conclusion The high transfer of Ag

+ ion from the aqueous phase to the

dichloromethane phase was observed with macrocyclic Schiff base

(III). It was found that macrocyclices have N6O4 or N4O8 donors sets

extracted Ag+ compared to the other transition metal cations

selectively. The composition of extracted Ag+ complexes was (1:2)

(L:M) and of Cu2+

complexes was (1:1) (L:M) for the ligand (III).

6. Acknowledgements We are grateful to the Department of Chemistry, Faculty of

Science, Damascus University, Syria for the support of this research.

References [1] WALKOWIAK W.; BROWN P.R.; SHUKLA J.P.; BARTSCH

R.A., 1987- Selective separation of alkali metal cations by bulk

chloroform membranes containing lipophlic crown ether

phosphonic acid monoethyl esters, J. Membrane Sci. 32,59.


20

[2] CHRISTIAN G.D., 1996- Analytical strategies for measurement of

lithium in biological samples. J. pharm. Anal. 14,889.

[3] UMMUHAN O.; HAKAN A., 2006- The synthesis of new N2S2

macrocyclic Schiff base ligands and investigation of their ion

extraction capability from aqueous media. Separation science

and technology, 41, 391, 401.

[4] RICHMAN J.E.; ATKINS T.J., 1974- J. Am. Hem. Soc., 96, 2268.

[5] IWATA M.; KUZUHARA H., 1989- Bull. Chem. Soc. Jpn, 62,

198.

[6] ATKINS T.J.; RICHMAN J.E.; OETTLE W.F., 1978- Org. Synth.

58, 86.

[7] CABRAL F.; MURPHY B.; NELSON J., 1984-. Inorg. Chim.

Acta. 90, 169.

[8] DREW M.J.B.; MURPHY B.P.; NELSON J.; NELSON S.M.,

1987- J. Chem. Soc. Dalton Trans. 873.

[9] SONE T.; OHBA Y.; WATANABE R.BULL., 1989- Chem. Soc.

Jpn. 62, 1346.

[10] SALIH I.; HAMID T., 2008- Synthesis of spectral studies of

macrocyclic Cu (II), N (II) and Co (II) complexes by template

reaction of 1,4- bi (3-aminopropoxy)butane with metal (II) nitrate

and salicylaldehyde derivatives. Journal of Molecular structure,

891, 157-166.

[11] SALIH I.; HAMID T., 2008- Prepared and characterization of

new macrocyclic shciff bases and their binuclear copper

complexes, Spectrochimica Acta PartA, 69, 896-903.

[12] ZIYADONOGULLARI B.; TOPAL G., 2001- Effeecy of

structure modifications of diaza-18-crown-6 on the extractability

and selectivity of univalent metal picratees, Ttalanta, 53,10834.


33

Improvement on AES Algorithm (Rijndael) through

Using Matrix Inverse and EC Mathematics over Finite

Fields

H. Al Najjar*, A. A. Shaar*, M. EB. Al Muhammad,*** *Dept. of Mathematics, Faculty of Science, University of Aleppo

**Faculty of Engineering, Computer Sciences, University of Al-Maamoun

***Postgraduate Student (PhD.) Dept. of Mathematics, Faculty of Science,

University of Aleppo

Abstract

The development subject of Cryptography Algorithms (CAs) is

considered one of the most important topics in the last years, because

of the large and fast development in the communications, computers

and networks, and the need for information security and data

protection methods (Cryptography methods).

A lot of researches have been dedicated in this field for

developing and innovating algorithms which suit this fast

development.

Complexity is considered one of the most important

specifications for any algorithm and its efficiency and power standard.

Rijndael is considered one of the most important algorithms in

Cryptography field.

In this paper, we have studied the specifications, various steps

and operations which were done in the algorithm. We investigated an

improvement on AES through using EC mathematics in its

transformations, and increasing the Complexity of algorithm.

Received 16/1/2011

Accepted 10/3/2011


53

Photon Diffusion from Diode Source of Wave Length

808nm in Biogical Tissue and Using Matlab for

Simulation

M. Anowr Batal, Ghoson Mearawi* Dept. of Physics, Faculty of Science, University of Aleppo


Abstract

Phototherapy efficaciousness is underling in previous

knowledge of the photons diffusion in biological tissues, and the

correct diffusion process contributes to the enhancement of this

therapy. Therefore, studying and realization of Light diffusion of

photons from diode source of wave length 808nm in biological tissues

are investigated using light diffusion equation, which can be solved

numerically by using forward Euler time integration method, which is

an explicit finite difference technique to find numbers of flounce

photons in biological tissue samples.

By using Matlab, we carried out 2D and 3D simulation about

flounce photons in biological tissue sample. Absorption coefficient of

tissue was determined to increase the efficiency of phototherapy by

adding photo sensitizer to biological tissue. Then compression of

photon diffusion in function of tissue depth was made in two cases of

natural tissue and tissue injected by photo -sensitizer.

Received 12/1/2011

Accepted 13/3/2011


37

Doping Effect of Zinc Oxide with Phosphorus

Oxide on Electrical and Electronic Properties M.A. Batal, H. Kanagha, M. Barghos *

Dept. of physics, Faculty of Science, University of Aleppo


Abstract

In order to study the effect of doping zinc oxide with phosphorus

oxide on its electrical and electronic properties, samples were prepared

from zinc oxide powder, doped with different rates of phosphorus

oxide powder with percentages (0, 0.5, 0.9, 1.1). The samples were

sintered at temperature 1200C0. Volt – Amp characteristics for

prepared samples show that the current increases with the increase in

P2O5 concentrations, and from I-V measurement, the barrier is higher

between the grain, and the non-linear factor has been determined for

the samples. The non-linear factor changed with varying the

concentration of P2O5. The non-liner factor is as small as possible

when the sample is doped with 0.5%. The measurement of impedance

spectrum was X (ω) = f (R (ω)) of the samples studied, and from these

measurements, the density of donors, activation energy and

intermediate states (trapped atoms) was determined. We noted that the

density of trapped atoms varied with the increase in doping

concentration, while the sample doped at rate of 0.5 percent shows

different behavior from the other sample. Considering that the samples

were prepared according to the Cole-Col model, the circle equation for

impedance spectrum has been demonstrated and it takes into account

the grains distortion of powder. The measurement also shows that the

equivalent circuit is resistant in parallel with capacitance.

Received 24/11/2010

Accepted 13/3/2011


39

Proposing Hybrid Algorithm in Optimizing the

Mathematical Models Used in Metals Rolling

Hamdo Al-Najar*, Abdul Rahman Hussian**, Zainab Shawa*** *Dept. of Mathematics, Faculty of Science, University of Aleppo

**Dept. of Control Engineering and Automation, Faculty of Electrical & Electronic

Engineering, University of Aleppo

***Postgraduate Student (PhD.) Dept. of Mathematics, Faculty of Science,


Abstract

In a previous work, we used a heuristic searching algorithm for

optimizing the mathematical model used in hot iron rolling process. In

order to obtain a constant thickness of the processed metal, the process

of hot iron rolling requires that the metal volume flow has a constant

value during the rolling process. The volume flow of different metals

depends on their kinds, and the objective of their use. Consequently,

this requires obtaining different flows within a pre-defined interval,

which may result in some shortage with respect to the used algorithm

for adjusting the speed of rolling engines, with an aim to obtain

constant volume flows.

This requires another consideration of the used algorithms in

order to obtain solutions that are more accurate.

In this paper, we developed a new heuristic searching algorithm

to tackle this shortage. The aim of the proposed algorithm depends on

combining the advantages of both the Genetic and Bees algorithms by

finding initial solutions using Bees Algorithm then improving these

solutions using a Genetic Algorithm to reach the optimal solution of

the problem understudy.

The result obtained using Genetic algorithm revealed a high

efficiency in adjusting the speed of rolling engines to obtain constant

volume flows.

The proposed algorithm is applied to iron metal, and it can be

applied to any other case studies representing different kinds of metals,

which require different volume flows.

Received19 12//2010

Accepted 16/3/2011


41

A Field Survey of Sugar Beet Root Rot Disease in Raqqa

Province, Syria Mohammad Matar*, Salah Corini*,

Mohammad Farhan Ismail**, Lama Togus*** *Dept. of Plant Protection, Faculty of Agriculture, University of Aleppo

**Agricultural Research Center in Raqqa, Syria

***Postgraduate Student (M.Sc.) Dept. of Plant Protection, Faculty of Agriculture,


Abstract

A field survey for sugar beet root rot disease was conducted in

8 major growing regions in Raqqa province to determine its incidence

and disease severity during 2008 and 2009 at three stages of plant age.

The samples were tested and the incidence and severity of disease were

determined according to sowing date, crop age, crop rotation, variety

and the site from Euphrates River. The causal organism was isolated

and cultivated from infected sugar beet roots. Its pathogenicity tested

results revealed that the disease incidence and severity were positively

proportioned with plant age at both autumn and spring sowing with

monoembryoic or multiembryoic varieties, and in 2009 they reached

34.00 and 22.64%, with severity of 1.79 and 1.02, respectively. Sugar

beet root rot incidence in 2008 and 2009 with autumn sowing fields is

significantly higher (77.1 and 76.1% respectively) as compared to

spring sowing fields (40.00 and 37.1% respectively). The disease

incidence percentage and severity were significantly higher in the

multiplembryoic sugar beet varieties cultivated fields and two sowing

periods (87.5, 46.7 and 87.55, 42.9%, respectively), compared with

monoembryoic varieties (66.7, 33.3 and 64.7, 31.3%, respectively).

Also, there were significantly low disease incidence rate and severity

(1.0%-0.08) in the fields rotated with: wheat, cotton, corn and sugar

beet, compared with non-rotation (51.18% and 1.85, respectively). The

results of pathogenicity and study of morphological characteristics of

the isolates showed that the fungus Fusarium oxysporum f. sp. betae

was the main causal organism of the disease in Raqqa province. Keywords: Field survey, root rot, Fusarium, sugar beet.

Received 16/1/2011

Accepted 22/3/2011


34

Res. J. of .Aleppo Univ. Basic Science Series No. 2011

The Effect of Using Diatoms Related to AL-Assad Lake's

Water as Organic Fertilization for the Plant

Vicia faba Rehab Dabbas

Dept. of Botany, Faculty of Science, University of Aleppo

Abstract

Results of our study showed that using Diatoms as organic

fertilizer has positive effect for getting higher yield and better

characteristic properties, and that was explained in details concerning

the growth of the plant Vicia faba, compared with control.

Our study showed that there were differences which contained

statistical significances.

We noticed for example an increasing in the plant fresh weight

by 1.38% and 5.67% after 30 days of planting and in the stage of

maturity, respectively.

The positive effect included the situation of the root system of

the plant too. We noticed an increase in the average of root length that

arrived at 11.9%, and an increase in the average of fresh weight that

arrived at 5.615%.

On the other hand, we did not notice, during our research, any

abnormal morphological variation (change) in vegetative organs.

Briefly, we can reach a very important conclusion pointing to

the possibility of using the organic fertilizer of Diatoms and Algae in

general instead of chemicals.

Received14 /1/2011

Accepted23 /3/2011


54

Preparation and Evaluation of Some Dental Waxes That

Can Be Used in Prosthetic Dentistry

Kamal Khoudary*, M. Zakaria Nassani**, Rami Badleh*** *Dept. of Chemistry, Faculty of Science, University of Aleppo

** Dept. of Removable Prosthodontics, Faculty of Dentistry, University of Aleppo

*** Postgraduate Student (MSc.) Dept. of Chemistry, Faculty of Science,


Abstract

Dental materials industry is one of the most important

industries which have not entered the Syrian Arab Republic yet despite

its importance in local markets.

We prepared 100 new dental waxes samples that can meet

dentists’ and dental technicians’ needs. We used new materials like

glyptal resin and phthalic anhydride. We worked to raise the ratio of

paraffin waxes in the dental waxes samples and reduce the ratio of

other natural waxes as bees’ wax which has a high price.

All samples were tested at several dental labs to get dental

technicians’ notices about samples quality. Then we chose 20 samples

that provided the best results in the dental labs. We tested them using

the local and the international standards specifications:

ADA (American Dental Association) ISO (International

Organization for Standardization) S.N.S (Syrian Arab Standards and

Metrology Organization)

We get several new dental waxes samples which meet the

requirements of local and international standards specifications.

Key words: dental waxes casting wax, bass plate waxes, sticky waxes.

Received 24/1/2011

Accepted 24/3/2011

Res. J. of .Aleppo Univ. Basic Science Series No. 76 2011

74

Sensing of Tin Oxide Thin Films Doped in Iron Oxide

toward H2S & H2 Gases

Ghassan Nashed, M.A. Batal, Fares Haj Jneed* Dept. of Physics, Faculty of Science, University of Aleppo


Abstract Tin oxide thin films doped with iron were deposited on glass

substrate using co-deposition dip coating sol-gel technique. The films

were doped with iron oxide at different concentrations (%2, %5, %7,

%10). The samples were called (S2, S5, S7, S10). Then they were

sintered for 2 hours at temperature 600ºC. I-V characteristics of the

thin film were studied at different temperature in the rang (150-250)°C.

Films sensing towered H2S gas were measured as a function of

different parameters such as (doping concentration, recovery time). It

is noted that films Sensing increased with increasing temperature,

doping concentration and gas concentration. Thin films sensing toward

H2 gas and (H2S-H2) mixture gases was measured at temperature

250ºC as a function of gas concentration. Selectivity factor was

calculated to H2S, and H2 Gases.

Received 6/2/2011

Accepted 10/4/2011


94

Purification and Treatment of Syrian Natural Zeolite by

Quaternary Ammonium Salts and Studying Its Surface

Properties

O. Dabbit, M. N. Mahayri* Dept. of Chemistry, Faculty of Science, University of Aleppo

*Postgraduate Student (MSc)

Abstract

We purified the Syrian natural zeolite that was grinded and

sieved to less than 160 μm. Initially, it was converted by replacing

earth alkali ions to Na-form by using EDTA at pH 4.0 for removing

Ca2+

and at pH 8.0 for removing Mg2+

. Then, the non-crystallic

metallic oxide, as iron oxide, was removed by aqueous soluble stable

complexes, using citrate buffer at pH 7.3. In the next step, we removed

the non-bio-oxidental organic material by H2O2 oxidation. Later, we

converted the raw natural zeolite (NZ) and the purified zeolite (PZ) to

Na-zeolite (Na-NZ, Na-PZ) by saturated-NaCl solution at 60 °C for

72h. In a later stage, we treated Na-NZ and Na-PZ samples with five

quaternary ammonium salts for 48h. We confirmed the zeolite surface

bonding by FT-IR, by studying the changes of the BET method surface

area, and the cationic exchange capacity (CEC) for all samples.

Key words: zeolite, cationic exchange capacity, surface area, quaternary ammonium

salts.

Received 2/3/2011

Accepted 13/4/2011


15

Effect of the Presence of the Polymer Layers on the

Mechanic Properties of Steel

Soda, Jallal*Akkad, Ahmad Nadim*

* Dept. of Physics, Faculty of Science, University of Aleppo

**Dept. of Basic Science, Faculty of Mechanical Engineering, University of Aleppo

Abstract

This research includes the study of the behavior of two

physically and mechanically different elements, and the relation

between the two element surfaces in terms of the structural

homogeneity on one hand, and the adherence and steadiness on the

other. The first material was from industrial polymer (PE) and the

second from industrial steel. The metal surface was coated with

multiple thin layers of Polymer (0.1-0.5µ), and the steadiest and most

homogeneous layer with the metal surface was determined (0.3µ). The

effect of this layer on the mechanical properties of the metal coated

with polymer was studied before and after the thermal treatment with

(air, water and oil). The layer was also compared with other metal

samples. The study concluded that the polymer layer plays a very

important role for the samples treated with water and oil, while it

negatively affects the samples treated with air.

Keywords: steel, thermal treatment, polymer layers, mechanical

properties.

Received 12/1/2011

Accepted 18/4/2011


35

Study of Some Optical Properties of Thin Films

Deposited by Chemical Solution Method CSD

Tarek Zarouri, Mohamed Rabie Hamzh, Zulfikar Mahmoud *

Dept. of Physics, Faculty of Science, University of Aleppo

*Postgraduate Student (MSc)

Abstract

The deposition technology of chemical solution method (CSD)

is somehow outdated but it gives good specifications of thin films

without the need for complicated equipment or the initial high-purity

chemical materials as is the case in organic or physical evaporation.

Various studies show that we can control the structure of thin

films according to the terms of interaction of temperature, pH of

solution, and the time of deposition. In this research, we will try to get

the best time for the optical properties (permeability and absorbency).

We will show in this research how to obtain Semiconductor

Thin Films for different time of deposition, the description of this

method, and the effect of this parameter on the optical properties of

these films.

Received 23/2/2011

Accepted 20/4/2011


55

Study of Enzymatic Esterification for Cottonseed Oil by GC-MS Technique

Saleh El-Kadri, Ahmad Al-Shaghel, Fadi Al-Rouh*

Dept. of Chemistry, Faculty of Science, University of Aleppo *Postgraduate Student (PhD.)

Abstract

After releasing fatty acids from cottonseed oil, we carried out

the direct esterification for free fatty acids with glycerol and

transesterification for triacylglycerols in crude cottonseed oil with

glycerol to synthesis monoacylglycerols by using the same enzymatic

catalyst (Novozyme435).

We obtained about (35%) of glycerol Monoolein and

monolinolein according to free fatty acid, and about (45.5%) of total

monoacylglycerols from total free fatty acid in direct esterification

reaction, and about (15.7%) in transesterification reaction.

The reaction has been carried out in specific conditions, and

monitored by GC-MS to study fragmentation and mass spectra of free

fatty acids of cottonseed oil and of the reaction products.

Some products from oxidation of unsaturated free fatty acids

were found in direct esterification. So these reactions should be done

in inert gas atmosphere. Transesterification does not need to be done in

inert gas but the yield is less than that in the direct esterification.

Keywords: Enzymatic esterification, Novozyme435, monoacylglycerols, Cottonseed

oil, GC-MS.

Received 24/2/2011

Accepted 27/4/2011


76

Determination of the Adsorption Properties and

Chemistry of H3PO4-Activad Carbon Obtained from

Wild Cherry Stones and Removal of Some Dyes from

Aqueous Solutions

M. Nasouh Alaya, Fatema El-Sejarieh, Abeer Amin*

Dept. of Chemistry, Faculty of Science, University of Aleppo

* Postgraduate Student (MSc.)

Abstract

A series of activated carbon (AC) obtained from wild cherry

stones activated by 20-85wt% H3PO4 and calcined at 723K was

selected in this study. The pH of the surface, pHzpc, textural properties

from N2 adsorption at 77K, and the amount of the surface functional

groups using Boehm's titrations were determined. The adsorption of

methylene blue (MB), rhodamine B (RB) and congo red (CR) from

aqueous solutions at 298K was also studied.

The results reveal that the surface pH of the selected ACs was

acidic, pHs=2.17-2.96, i.e. the ACs are of Type L. The pHzpc values are

in the range 4.17-4.70. Both pHs and pHzpc depend on the activation

percent; they are minimal for 35wt%H3PO4-AC. The nitrogen

adsorption isotherms for ≤35wt% ACs are of reversible type I, whereas

for ≥50wt% ACs are between types I and IV with hysteresis loops.

The specific surface area, total pore volume and micropore volume are

maximal at 50wt% activation. The values of SBET, St, Sα and SDR are in

good agreement for ≥50wt% ACs, but for ≤35wt% ACs the SBET

values are lower. The t- and αs-plots show downward deviations

indicating thus that the selected ACs are mainly microporous carbons.

The amounts of the different surface functional groups depend

on the activation percent. The total amount of the acidic groups is

maximal for 65wt% AC. The total amount of the basic groups is

decreased sharply when the activation increased from 20 to 35wt%;

after that it increased gradually up to 65wt%.

The adsorption isotherms of MB, RB and CR from aqueous

solutions are of Langmiurian type. The adsorbate/adsorbant

interactions as well as the maximum uptakes are in the order:

Keywords: Activated carbon, surface pH, pHzpc, textural properties, surface groups,

MB, RB, CR.

Received 12/4/2011

Accepted 2/5/2011

Dr. Alaya, Dr. El-Sejarieh & Amin

75

MB>RB>CR, which is in accordance with the dye volumes. The

surface accessible to dye molecules is a small fraction of the total

surface area of the ACs, due to microporous nature of the ACs and also

to the nature of the charge of the dye. The molecules of the dyes in

aqueous solutions are cationic, zwitterions and anionic for MB, RB

and CR, respectively.

Res. J. of .Aleppo Univ. Basic Science Series No. 67 2011

95

Calibration of High Energy Photon Beams for Medical

Linear Accelerator in Damascus Medical Hospital

(Damascus) Using Cylindrical Ion Chambers in Water

Phantom

A.Talleb*, F. Bador **, A .Salah***, F. Salh**** *Dept. of Physics, Faculty of Science, University of Aleppo

** Dept. of Imaging Radiations, Faculty of Medicine, University of Aleppo

***Dept. of Physics, Faculty of Science, University of Al Baath

****Postgraduate Student (MSc.) Dept. of Physics, Faculty of

Science, University of Aleppo

Abstract

In this research, we have calibrated photon beams that have high

energy (6-15 Mv) in three dimension water phantom using medical

linear accelerator (Electa 1135), medical Cylindrical ion

chambers 8304, 8305, 65RK RK FC G and dosimeter (Dose 1).

This study was conducted in Damascus medical hospital

starting (October 2009) to (October 2010). We have had mechanical

tests to check linear accelerator, study percentage changes for dose in

depth (PDD), determine kind of radiation beams using quality index

for photon beams ( 20

10TPR ) depending on report IAEA (398) and study

properties of profile for radiation beams that include Symmetry,

Flatness and penumbra. At last, we have calculated the absorbed

radiation dose for phantom beams.

Received 5/1/2011

Accepted 3/5/2011

Res. J of Aleppo Unit Basic Science Series No. 76 2011

16

Study of Solution of Boundary-Value Problem on a

Geometric Graph with Generalized Kirchhoff Condition

Zakria Nout*, Moa’Az Abdelmajeed**, Manal Swid***

*Dept. of Mathematics, Faculty of Science, University of Aleppo

**Dept. of Basic Sciences, Faculty of Electrical and Mechanical Engineering,

University of Damascus

***Postgraduate Student (MSc.) Dept. of Mathematics, Faculty of Science,


Abstract

Consider the problem

(1) ( ) ( )p x u q x u f x

(2) 0u

Where is an open connected geometrical graph in n

, is the set

of boundary tops of , p , q, f are uniformly continuous functions on

( is the set of ribs of ) and p is a positive function on .

We prove the existence and uniqueness of the solutions of the

problem (1), (2) in a special space of functions which have on a

uniformly continuous second derivative and they satisfy the

generalized Kirchhoff condition in every internal node a of the graph :

( )\

( ) ( ) ( ) ( ) ( )i i ij i j i i

j I a i

a u a k a u a u a k a u a i I a

Where ( ) : iI a i a and ( ) , ( )i ij ik a k a a are fixed and

positive numbers.

Then we prove the existence of Green function for this

problem. Key words: Differential equation, Geometric graph, boundary-value problem,

Solvability, Green function.

Received 24/3/2011

Accepted 4/5/2011


36

Effect of Sodium Dodecyl Sulfate on Hydrodynamic and

Structural Properties of Polyacrylonitrile

Nazeeh Kutaish Said Abdel Nour, Muhammad Aref Alkhdear*

Dept. of Chemistry, Faculty of Science, University of Aleppo

*Postgraduate Student (M.Sc.)

Abstract

Polyacrylonitrile (PAN) components were determined by the

use of infrared spectroscopy FT/IR. Viscosity and specific electrical

conductivity were studied in N,N-dimetheylformamide (DMF)

medium, at different concentrations and temperatures in presence or

absence of Sodium dodecyl sulfate (SDS). Critical concentration of

micelle formation (CCMF) of SDS was determined in DMF.

Crystalline structure of PAN in solid phase was determined by X-ray

diffraction (XRD) and scanning electron microscopy (SEM).

Keywords: Polyacrylonitrile, Fiber, spinning, mechanical properties, surfactants.

Received 22/3/2011

Accepted 8/5/2011

Res. J. of Aleppo Univ. Basic Sciences Series No 76 2011

56

Results on Graded Ring by Orthogonal Band and by

Completely Regular Semigroup Whose Maximal

Subgroups are Polycyclic-by-Finite Group

Nader Elnader, Samir Saad, Ali Khallawy* Dept. of Mathematics, Faculty of Science, University of Aleppo

*Postgraduate Student (PhD.)

Abstract

Let S be a semigroup and sSsRR

be a S -graded ring with

the unity. We proved that: If S is an orthogonal band, 0oR .

Then:

i) ),( SRSupp is finite.

ii) The unity 1 is written in the form:

ni ,...,2,1 0ii ss Ra ;

n

i

sia

1

1

Where ),...,2,1( niais

is the unity of the subring is

R and nsss ,...,, 21

are different elements of S .

iii) The classical right ring of quotients of R exists if the classical right

ring of quotients of every nonzero homogeneous compound exists.

Also we proved that we can write the ring R as a direct sum of

subrings of R where every subring has an Artinian ring of right

quotients when S is a finite completely regular semigroup and every

maximal subgroup of S is polycyclic-by-finite group and ),( SR is

strong gradation, and every nonzero homogeneous compound whose

index is an idempotent of S has an Artinian ring of right quotients.

Keywords: orthogonal band, polycyclic-by-finite group, completely regular

semigroup, graded ring, strong gradation, right ring of quotients, the

classical right ring of quotients.

Received 22/3/2011

Accepted 9/5/2011


67

A Comparative Study of the Competence Used in Some

Immuonotests for the Diagnosis of Toxoplasmosis

Sabah Blaj

Dept. of Animal Biology Faculty of Science, University of Aleppo

Abstract

In this research, four immunological tests have been compared

for the diagnosis of Toxoplasmosis to know the sensitivity and

specificity of each method and propose the best

The tests have been conducted on 93 samples of human serum

from males and females with an average age (17-58 years) from

Aleppo. The obtained results were as follows: The percentage of

infection (acute and chronic) in general (62.37%): males (55.56%) and

females (64%). The symptoms of toxoplasmosis and abortion

developed only in 16 married females, 13 samples (81.25%) of which

were positive for the tests.

The positivity percentage in the tests has been as follows:

Indirect Hemagglutination test (IHAT): (38.71%), (55.56%) of

them were acute infection.

Indirect Immunofluorescence test (IIFT): (51.61%), (70.83%) of

them were acute infection .

Immunoblot EUROLINE (Strips): (49.46%), (63.04%) of them

were acute infection .

Enzyme-linked Immuno sorbent Assay (ELISA): (62.37%),

(60.34%) of them were acute infection.

The results indicated that the best serological methods for the

diagnosis of Toxoplasmosis were: ELISA, Immunofluorescence,

Euroline (Strips), and the indirect Hemagglutination, respectively.

Keywords: diagnosis of toxoplasmosis, Toxoplasma gondii, Immunological tests,

Hemagglutination, Immunofluorescence, Enzyme immunoassay.

Received 22/2/2011

Accepted 9/5/2011


96

Isolation of Some Microbial Species Causing Infections

of the Tissues Supporting the Teeth and Study of Their

Sensitivity to Antibiotics Hasan Hammadi*, Mazen Kabbani**, Shaza Issa***

* Dept. of Plant Life, Faculty of Science, University of Aleppo

** Dept. of Periodontal Diseases, Faculty of Dentestry,


***Postgraduate Student (PhD.) Dept. of Plant Life, Faculty of Science,


Abstract

Natural gums are pink, consistent with the teeth, thick, and not

swollen, but with inflammation they turn red and swollen and start

bleeding. Actually these symptoms vary depending on the stage of

inflammation and its quality. The accumulated plaque and sediment on

the gums and teeth reach the periodontal pocket.

The pathogenicity of plaque depends on the existence of

different types of bacteria and their products in the gutter gum.

Whereas the heavy and high bacterial load leads to an imbalance in the

relationship of natural balance between bacteria and oral bacteria host,

but in the case of lack of host resistance and the weakness of the body's

natural defense mechanisms, this balance is disturbed causing an

infection to the periodontal tissues.

In our study we have obtained 257 isolated bacteria from

patients of the Department of gum disease in the Faculty of Dentistry

at the University of Aleppo. The results showed that these isolates

identify seven types of bacterial genera, belonging to seven species of

bacteria, as follows: Actinobacillus actinomycetemcomitans, Bacillus

coagulans, Corynebacterium matruchotii, Eikinella corrodens,

Enterococcus faecalis, Paenibacillus macerans, and Streptococcus

Sanguinis. The recent study found that the more isolated species from

the periodontal tissues is the species Corynebacterium matruchotii

with rate 25%, while the least isolated one is the species Streptococcus

Sanguinis with rate 3.9%. After examination of the sensitivity of the

species to antibiotic treatment, the results showed that all species have

shown sensitivity to the antibiotics Imipemem and Azitromycine,

while all species have shown resistance to high levels of Penicillin. Keywords: Periodontitis Tissues, bacterial plaque, periodontal disease tissue,

gingival pocket, antibiotics.

Received 6/4/2011

Accepted 9/5/2011


17

Studying the Building and Mechanical Features of the

Metal Mixtures from: (AL1-x-yMgxCuy) and

(Al1-xMgx) Brought by Pressure

Mohammad Saleh Himmami, Triq Zarori, Mohammad Halabi* Dept. of Physics, Faculty of Science, University of Aleppo

*Postgraduate Student (MSc.)

Abstract

This research includes two groups of dual metal mixtures

(Al-Mg), and the triple (Al-Mg-Cu). These elements were liquated

together till (660C0) during (6) hours, then they were cooled slowly.

After that, they were pressed to be circular tablets at

(15 Ton/Cm2). These fetched mixtures were described physically.

Then a comparison had been drawn between the results to study the

effect of adding brass in a constant rate on the properties of the fetched

dual mixtures.

We studied the crystallized configuring of the fetched mixtures

by using the Ultra-violet rays limping way. The result showed that

adding the brass to the dual mixture had led to form a new component

CuAl2 which affected the properties of the fetched dual mixtures.

Some mechanical attributes had been studied as the (Hardness)

by using FIGURES device to gauge the hardness. It was clear that the

hardness had increased with adding brass to the dual mixture at a

constant rate. Received 30/3/2011

Accepted 10/5/2011


37

Lead Determination by Applying Electrochemical

Method Using PEDOT: PSS Carbon Modified Electrode

Sensor

Nael Yasri, Hassan Seddik and Ahmad Halabi* Dept. of Chemistry, Faculty of Science, University of Aleppo

*Postgraduate Student (MSc.)

Abstract

Lead ions were determined in aqueous environmental samples

by applying cycle-voltamperemetric analysis with PEDOT:PSS

modified carbon electrode (sensor), that has been characterized as

simple and with low cost and toxicity. At optimum conditions, the

Cyclic voltammograms for lead ions using PEDOT:PSS modified

electrode exhibit two peaks: the first corresponds with oxidation at (-

360±10) mV, whereas the second corresponds with lead reduction at (-

550±10) mV. Linearity was within the lead ions concentration range of

1.00 x 10-5

- 2.50×10-4

mol.L-1

(r=0.998), with linear correlation

coefficients not exceeding the value of 3.06%, and the limit of

detection (LOD) reaching 0.185×

mol.L-1

. The method shows

very high selectivity and sensitivity for lead ion determination in some

real environmental samples, and at the same time, it is in agreement

with the result obtained from atomic absorption spectroscopy

measurement.

Received 22/3/2011

Accepted 10/5/2011

No. 76 2010 Res. J. of Aleppo Univ. Basic Science Series

57

Study on Boundary Value Problem of Functionally

Graded Sandwich Plate under Effect of Mechanical and

Thermal Loads

Bachir Nour Kharrat, Ali Hinnawi, Hussam Al-Din Alawa*

Dept. of Mathematics, Faculty of Science, University of Aleppo

* Postgraduate Student (M.Sc.)

Abstract

In this paper, we proposed the formulation of boundary value

problem for Functionally Graded Sandwich plate, simply supported by

the action of Mechanical and Thermal Loads. We obtained the

equilibrium equation by applying virtual work principle and the

Divergence Theorem. The components of stress couples were found by

using the stiffness coefficients, and by depending on derivatives of

these components. We wrote the boundary value problem

corresponding to the bending of the functionally graded sandwich plate

under effect of mechanical and thermal loads. We proved existence

and uniqueness of the problem by using theory of Lax-mailgraim and

obtained the analytical solution by applying the levy method in the

case of sinusoidally distributed loads.

Finally, several kinds of functionally graded sandwich plate

were reviewed. In order to ensure accuracy and effectiveness of the

applied method, we did a numerical application to show the effect of

the volume coefficient exponent and dimensions ratio of plate. We

used Matlab program to obtain the curves graphs that represent the

displacement in the studied plate.

Key words: Functionally Graded Sandwich plate - boundary conditions - mechanical

and thermal loads – virtual work principle- Divergence Theorem-LAX Mailgram

theorem- levy method.

Received 28/2/2010

Accepted 16/5/2011


77

Optical Response for WO3 Thin Film Used as Smart

Windows

Mounir Al Hamed*, Malek Ali**, Giath Marate***

*Dept. of Physics, Faculty of Science, University of Aleppo

**Dept. of Physics, Faculty of Science, University of Albaath

***Postgraduate Student (PhD.) Dept. of Physics, Faculty of Science,


Abstract

In this paper we study the optical response for a Tungsten

Oxide Thin Film prepared by Sol – Gel Technique using spin coating

Method at 3000 rpm for 400-1000 nm transmission spectroscopy as a

comparative study with theoretical spectrum. We found that there were

good transmission values for 150 nm thickness (86-95%) in both the

practical and theoretical spectra.

Received 9/2/2011

Accepted 16/5/2011


79

Study of Stability of Optical Response in the FXG Gel

Dosimeter

Abdallah Taleb Dept. of physics, Faculty of Science, University of Aleppo

Abstract

There are many gel solutions used for dose measurement.

Ferrous sulphate Xylenol orange Gel (FXG) was studied by many

researchers for dose calibration in medicine for the treatment planning

of tumors by ionizing radiation.

In this work, some dosimetric properties of gel solution FXG

were studied to calibrate and improve the performance of solution

using optical technique.

The optical performances of FXG dosimeter were studied in the

wavelength rang between 300nm to 700nm. We have a large peak at

440nm for non-irradiated solution and after irradiation we have an

absorption peak centered around 585nm by the increase and decrease

of the dose at about 440nm.

The stability of optical response in FXG gel dosimeter was

studied before irradiation. The stability is better for solutions

maintained under refrigeration and light protected and the optical

absorbance change is less than 1% an hour.

Received 13/4/2011

Accepted 18/5/2011


18

The Use of Microorganisms to Produce Biofuel

(Bioethanol) from the Corn Cobs

Abdullah Jhar, Mahmud Kashtari, Alisar Abdel- Latief*

Dept. of Botany, Faculty of Science, University of Aleppo

*Postgraduate Student (M.Sc.)

Abstract

This research aims to produce Bioethanol (the most available

Biofuel) from corn wastes (corn cobs). Agrowastes generally consist of

three essential components: cellulose which is polymers of glucose

(easy to be fermented), hemicelluloses which is polymers of pentose

(difficult to be fermented), and lignin which is polymers of phenyl

compounds (not fermented). Bioethanol production includes three

steps: pretreatment to delignification, hydrolysis to release sugars, and

fermentation by the yeast; Sacchromyces cerevisiae, and

Sacchromyces cerevisiae strain V30.

The research shows that the best pretreatment conditions were

at 2% H2O2 hydrogen peroxide and pH=11.5, the weight loss average

for the best group was (107.6)g, and the best yield of glucose (17.84

g/200ml) during dilute sulfuric acid hydrolysis was at 2% H2SO4.

Fermentation results showed relatively close results where S.cerevisiae

strain V30 gave 4.40% v, Bioethanol, and S.cerevisiae (Backers yeast),

gave ethanol 4.33% v, Bioetanol.

Keywords: biofuel, bioethanol, pretreatment, hydrolysis, fermentation.

Received 18/4/2011

Accepted 21/7/2011

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