ISSN: 1813-0410

Volume 8, Issue 3

Volume 8, Issue 3, Summer 2012, Page 1-110

Effect of MWCNT on Electro-Optical Properties of Liquid Crystal

Sudad S. Ahmed; Rawa K. Ibrahim; Asama N.Naje; Kais Al-Naimee

journal of kerbala university, Volume 8, Issue 3, Pages 1-6

Dispersions of multi wall carbon nanotubes (MWCNTs) in liquid crystals (LCs)type 5CB have attracted attention due to their unique properties and possible applications in photonics and electronics. The results of the investigations of improved the electro-optical properties of liquid crystal optical switch are being presented here. The addition of MWCNT showed fast response time ,fast rise time,and lower threshold voltage.

Investigation of structural, optical and electrical properties of TiO2 and ZnO thin films

Samer. Y. Al-Dabag; Ghuson. H. Mohammed; Sudad. S. Ahmed

journal of kerbala university, Volume 8, Issue 3, Pages 7-16

This paper reports the investigation of structural, optical and electrical properties of TiO2 and ZnO thin films. The thin films were prepared by pulsed laser deposition (PLD) method using pulsed Nd:YAG laser at 1064nm wavelength and repetition rate 6Hz. Different pulse of shot (200, 500, 800) and different thickness of TiO2 (150, 250, 400)nm, ZnO (250, 400, 550)nm. were used at constant energy (800 m J).
Morphology of the deposits materials were studied by Atomic Force Microscopy (AFM), results indicated that all thin films have nanoscale grain size around 90 nm.
The linear optical measurements showed that nanostructure (TiO2 and ZnO) thin films have direct energy gap.
The Hall effect measurements confirmed that the nanostructure (TiO2 and ZnO) thin films are n-type and the charge carriers concentration (n) were increased with increasing pulse shot. Hall mobility (H) decreases with the increasing of pulse shot thin films.

Effect of Indium Tin Oxide (ITO) Nanoparticles on the Optical Properties Of PMMA Polymer

Asama Natik.Naje; Salma M. Hasan; Estabrak Talib

journal of kerbala university, Volume 8, Issue 3, Pages 17-23

In this work the optical properties of the PMMA polymer doped with different concentrations of ITO nanoparticles had been studied. All samples were prepared by casting technique with thickness of 1 mm. The optical properties ((absorption, transmission, absorption coefficient, extinction coefficient and refractive index) had been investigated. The doped composites have shown shifted toward the visible region. Whereas measured energy gap for pure and doped polymer shows decreases in the energy gap from 5.5eV to 3.5eV. The refractive index of pure polymer decreases as wavelength increase, where the refractive index of the doped polymer increases with increasing ITO concentrations.

Preparation and characterization of ZnO nano-particles

Asmaa Sh. AL-Gurabi; Shaimaa s. Al-Ani; Ekram A.Al-Ajaj

journal of kerbala university, Volume 8, Issue 3, Pages 24-34

ZnO plays an important role in many semiconductors technological aspects. In the present work zinc oxide nano particles were prepared by chemical method , using ( Zn (NO₃)₂.6H₂O) and (NaOH)with different concentrations(0.25,0.5,0.75, and,1)M(which lead to different PH) at 70ºC,and study the effect of temperature on the shape and particle size . A variety of techniques like X-ray diffraction (XRD),Scanning Electron Microscopy (SEM)and (AFM ). X-ray diffraction revealed the quartzite structure of ZnO . The obtained show that no impurities were found in the XRD pattern. Also the diffraction peaks are intensive and very sharp. Thus high purity hexagonal ZnO nanocrystals could be obtained by this synthesis process, and (SEM)and (AFM )show that the result were nano particle with particle size (15-30),(20-35),and(20-40)nm for the three first concentration ,and for the last one, the SEM image demonstrates clearly the formation of Short rods ZnO nanoparticles of diameter ~25-62 nm and length ~ (200 nm -500 nm) .

The Effects of Operating Parameters on The Morphology of Electrospun Polyvinyl alcohol Nanofibres

Akram R. Jabur; Laith K. Abbas; Safa M. Muhi Aldain

journal of kerbala university, Volume 8, Issue 3, Pages 35-46

في هذا البحث تم تحضير انسجه من البولي فينيل الكحول بطريقة البرم الالكتروني حيث تم دراسة تأثير العوامل التشغيلية و منها الفولتية المسلطة , معدل التدفق للسائل البوليمري والمسافة بين الابرة الي الجامع.تم اجراء بعض الفحوصات الشاملة للانسجه البوليمرية النانويه تتضمن قطر الليف بالحسابات الاحصائية من صور المجهر الالكتروني الماسح.البولي فينيل الكحول تم اذابته في ماء مقطر بتركيز (10%). المحلول البوليمري برم الكترونيا في ظروف عملية مثل الفولتية المسطله (25,20,15,10,5) كيلوفولت, المسافة بين حافة الابرة والجامع (22,20,15,12,8,4) سم ومعدل التدفق (10,1,0.8,0.5,0.2) مل.ساعه- 1,القطر الداخلي للابرة المستخدمة (0.6 سم ),الجامع للالياف هو صفيحة المنيوم. عند الزيادة الفولتية العاليه المسلطه بثبوت الظروف الاخرى يلاحظ تزداد ان القوة الكهروستاتيكية الى ان تتجاوز الشد السطحي للبوليمرحيث يسمح نفث البوليمر للنفاذ من حافة الابرة ليصل الى الجامع.عند زيادة معدل التدفق مع ثبوت العوامل الاخرى, أن فولتية مسلطه عاليه بقيمة 25 كيلو فولت تنتج أفضل.بزيادة معدل تدفق السائل البوليمري يحصل زيادة كميات تدفق السائل البوليمري اما عند زيادة عالية جدا لمعدل التدفق تنتج الياف مسطحة .تاثير المسافة بين حافة الابرة والجامع بثبوت الظروف الاخريلاحظ معدل قطر الليف يقل تدريجيا من (857نانومتر) على مسافة (4 سم ) الى (600نانومتر) على مسافة (22سم), حيث ان المسافة الكبيرة تسمح للمذيب بوقت اطول للتبخربشكل كامل واستطاله اكثر للالياف.

Study of The Effect of Nitrogen Atoms on The Electronic Properties of Azulene Ring:B3LYP/ DFT Calculations

Ghaidaa A. Hafedh Jaber; Basim Abdullattif Ghalib; Fatin F. Mahmood; Mohammed Sabah; Abdulrazzaq M. Kadhim; H. I. Abbood

journal of kerbala university, Volume 8, Issue 3, Pages 47-58

Theoretical study of the effect of adding nitrogen atoms in place of carbon atoms on the electronic properties of azulene ring was performed using DFT with B3LYP/6-31(d, p)basis sets. The optimized structure, total energies, electronic states, energy gaps, ionization potentials, electron affinities, chemical potentials, global hardness, softness, global electrophilictity, dipole moment and dipole polarizability were calculated. The harmonic vibration frequencies were calculated and compared with available experimental data. The results showed a decrease and increase in energy gap of azulene depends on the number and position of nitrogen atoms in the ring and improve the electronic properties for the new structures.

Behavior of Optical Parameters of CuZnSnO4Thin Films

Salma M. Shaban

journal of kerbala university, Volume 8, Issue 3, Pages 59-67

A compound (CuZnSnO4) as thin films is deposited by thermal evaporation method at room temperature onto glass substrates at film thicknesses (100 & 300) nm. The structure of CuZnSnO4films is amorphous as indicated by X-ray diffraction pattern. Optical parameters like, transmittance, energy gap, constants of direct transition, Urbach energy, refractive index, extinction coefficient, and complex dielectric constant are studied. A good property for this compound, it can be used as window layer or absorbance layer with the variation of film thickness.

Preparation and evaluation of the efficiency of nano composite thin film for the production of hydrogen gas

Haleemah J. Mohammed; Kassim M. Sahan; H. Jawadm; Basher; Roaa Sh. Mahmood

journal of kerbala university, Volume 8, Issue 3, Pages 68-78

In this research had been studied the preparation and the study of the efficiency of Composites nano thin film for the production of electrodes used in the production of hydrogen gas through the Electrolysis cell consists of these Anode nano )Co: Mn, Wo3) either electrode cathode nano (NI. Cr .MO) In the water electrolysis process the hydrogen is produced by electrochemical splitting water molecules (H2O) into their constituent hydrogen (H2) and oxygen (O2). this thin films was prepared on glass substrates, also Aluminum oxide by using deposition . ..structured characteristics was studied through the analysis of X-ray diffraction (XRD) of the prepared film for determining the yielding phase which are to set the with standard tables . Also, the sample was tested atomic force microscope to identify the roughness of prepared films surface and the study of the efficiency of this cell to the electrode material, the distance between the electrodes, And has been the study of the volume of gas output ,voltages with change time and current.

Micro Raman scattering and structural investigation of nanocrystalline Nd:KTP

A. Cheraghi; A.S.H. Alattar; R. Malekfar

journal of kerbala university, Volume 8, Issue 3, Pages 79-82

In this work we report the synthesization process of nanocrstalline Nd:KTP powders by modified sol-gel method. The results of XRD studies indicate that KTP nanocrystallines doped by Nd has orthorhombic phase. By using micro Raman back scattering and FT-IR transmission spectroscopies, the lattice modes of the synthesized nanocrystalline products have been investigated. The structural and the grain sizes determination for the synthesized samples were measured using the XRD patterns and the Debye-Scherrer formula. These data are in close agreement with the grain sizes determined by the SEM slides. It can be claimed that XRD analysis and micro Raman backscattering spectroscopy are suitable methods to study the quality of nanocrystalline materials including KTP family

Investigation the use of nanoclays on the modification of Aeolian Sand

Sofian; J. and Nikudel

journal of kerbala university, Volume 8, Issue 3, Pages 83-93

Nano-clays are a broad class of naturally occurring inorganic minerals in the form of plate-like of aluminosilicate layers with thickness between 1 nanometer to 10 micrometers. Due to the very small sizes of nanoparticle, they provide a large specific surface area which capable them to absorb water and fill the voids within the soil particles.
The aim of this paper is to investigate the use of nano-clays for modifying the engineering properties of aeolian sand. The aeolian sand covers a large areas in Central Iran and their movements affect directly on the performance and stability of infrastructures such railways and roads networks of the region.
The mineral composition of the sand mainly consists of quartz grains and the soil type is classified as poorly graded materials. In order to evaluate the effect of micro and nano clay on modification the geotechnical properties of the sand, different percentage of 0.5%, 1%, 2% and 4% of micro and nano clays were mixed with the sand and number of tests such as compaction test, direct shear test are conducted on the samples. The result shows that maximum dry unit weight and lowest optimum moisture content were obtained when 4% nano-clay mixed with the sand. It was also was noted that the increment of nano-clay and micro-clay causes gradual increases and gradual decreases of the shear strength of the sample, respectively.

Preparation of Epoxy Nanocomposites and Studying Their Mechanical, Thermal and Morphology Properties

Jalil Raheef Ugal; Muna Emad Abd Al-Fattah

journal of kerbala university, Volume 8, Issue 3, Pages 94-99

Epoxy resin was used as a matrix , reinforced by nanosilica as a filler in different percentages ( 1, 3, 5, 7 and 10) % to prepare epoxy nanocomposites and a comparison between manual mixing and ultrasonic mixing by studying mechanical properties (tensile strength) , thermal properties ( Limiting Oxygen Index (LOI)) and morphology ( Scanning Electron Microscope (SEM)) to get the best improvement results .
The best results were for ultrasonic mixing , at additive content 5% for tensile strength, and noticeable increment in all limiting oxygen index measurements.

Biological improvement of sandy soil by microbial induced carbonate precipitation

Mashaalah Khamehchiyan; Karim Rowshanbakht; Mohammad Reza Nikudel; Reza H. Sajedi

journal of kerbala university, Volume 8, Issue 3, Pages 100-110

Microbial-induced calcite precipitation (MICP) is a relatively green and sustainable soil improvement technique. It refers to a chemical reaction network that is managed and controlled within soil through biological activity and whose byproducts alter the engineering properties of soil. To treat soil, first, the microbial population in-situ is augmented by the injection of additional urease positive bacteria and then reagents are added. A series of laboratory test was carried out to investigate the potential application of the technique in improving the strength and impermeability of a sand specimen and utilized techniques, materials, methods and empirical process during the test are explained. The results showed that as a result of the calcite precipitation, shear wave velocity increased up to 1000m/s and UCS strength increased to about 300Kpa and permeability of soil decreased significantly upon MICP treatment.