Engineering and Technology Journal

Keyword is useful for a various purposes including labeling, summarizing, indexing, categorization, searching, and clustering. In this paper we will extract keywords from the Arabic text in order to classify it. The proposed system classify any Arabic text through simple statistic and linguistic approaches by extracting the keywords of the text (with their frequency that appear in the text) depending on a Date Base of a particular field (in this work we choose computer science field). This Data Base is represented using one B+ tree for keywords and the other DataBase for non-keywords. The proposed system was implemented using Visual Prolog 5.1, and after testing, it proved to be a valuable for Arabic text classification (From the viewpoint of accuracy and search time).

Deposition of the Titanium oxide (TiO2) particles on glass and the Si substrates was materialized for a wide range of temperatures (100-400)°C; using PLD technique at constant laser energy 800 mJ of frequency doubled Nd: YAG laser wavelength of 532nm running at 10 Hz rate and 10ns duration pulses. UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM), Atomic Force Microscope(AFM), electrical conductivity (σdc), Hall coefficient (RH) and (I-V) and (C-V) measurements were employed to examine optical, morphological and electrical properties of the deposited films. 85% film transparency was accomplished with optical band gap of (3.25 – 3.64) eV.(I-V) characteristics showedan enhanced TiO2 p-n junction thin film solar cell efficiency by 1.6% at 400°C.

In this paper, Nano crystalline TiO2 and CuO additive TiO2 thin films were successfully deposited on suitably cleaned glass substrate at constant room temperature, and different concentration of CuO (0,5,10,15,20)% wt using pulse laser deposition(PLD) technique at a constant deposition parameter such as : (pulse Nd:YAG laser with λ=1064 nm, constant energy 800 mJ ,with repetition rate 6 Hz and No. of pulse (500).The films were annealed at different annealing temperatures 423K and 523 K. Effect of annealing on the morphological and electrical were studied. Surface morphology of the thin films has been studied by using atomic force microscopes (AFM). AFM measurements confirmed that the films have good crystalline and homogeneous surface. The Root Mean Square (RMS) values of thin films surface roughness are increased with the increase of annealing temperature. Also, The grain size increases with the increasing of concentration of CuO and annealing. The temperature dependence of the electrical conductivity and the activation energy at temperature ranging from (293-473)K of the as-deposited and films annealed at different annealing temperatures have been studied. The results show that as the film concentration of CuO and conductivity increases, while the activation energy(Ea1,Ea2) decreases. Both, the annealing and composition effects on Hall constant, RH, charge carrier concentration (NH), Hall mobility. Hall Effect are studied. Hall Effect measurements show that all films have n- type charge carriers and the concentration and annealing increases carriers concentration while the mobility decreases .

SnO2 nanoparticles were prepared by laser ablation of tin in methanol at room temperature. The particles were characterized by means of TEM, AFM, FTIR, UV-Visible absorption spectrum and electrical properties. AFM micrographs show that the obtained material is spherical nanoparticles, the size and size distribution of which depends on the experimental conditions.
From FTIR spectrum show the peak absorption of SnO2NPssuspension at 657 cm-1.
It is found that the band gap energy of SnO2NPs is higher than that of bulk SnO2 due to the decreases in the particle size according to the quantum confinement model.
From the J-V characteristics Al/SnO2 NPs/c-Si/Al hetrojunction the values of ideality factor for these devices is greater than unity which can be attributed to the recombination of electrons and holes in the depletion region as well as the tunneling effect depending on both sides of the heterojunction and on the presence of defect states.

In this work, Nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates at 300 °C. TiO2 thin films were then annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structure, morphology and optical properties were studied. The X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) measurements confirmed that the films grown by this technique have good crystalline tetragonal mixed anatase and rutile phase structure and homogeneous surface. The study also reveals that the RMS value of thin films roughness increased with increasing annealing temperature .The optical properties of the films were studied by UV-VIS spectrophotometer. The optical transmission results shows that the transmission over than ~65% which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient increase with annealing temperature.

The influence of oblique angle deposition on the surface morphological and microstructure of metallic cadmium films are studied. The films were deposited normally and obliquely at different angles (0º, 50º and 70º) by vacuum evaporation technique. XRD technique used to study the crystalline structure of these films and shows that the polycrystalline nature of these films and All layers irrespective of deposition parameters develop a preferred (002) plane. The grain size increased with the increase of deposition angle and clearly facetted morphology was observed. The surface morphology of the deposited materials has been studied using atomic force microscopes (AFM) and optical reflection microscope. The AFM results demonstrate that the film deposition at higher oblique angle (70°) has higher surface roughness. Reflection microscope results showed that the smoothness and homogeneity of the films are decreasing with increasing the deposition angle d), and the surface roughness increased with increasing angle. The optical characteristics of the prepared thin films have been investigated by UV-VIS spectrophotometer in a wavelength ranging (350-900) nm and shows by increasing the inclination angle of deposition will lead to transmission decreases of the films.

Keywords are useful tools as they give the shorter summary of the
document. Keywords are useful for a variety of purposes including
summarizing, indexing, labeling, categorization, clustering, and searching, and
in this paper we will use keywords in order to find the relevance degree
between an English text and its title.
The proposed system solves this problem through simple statistic (Term
frequency) and linguistic approaches by extracting the keywords of the title
and keywords of the text (with their frequency that appear in the text) and
finding the average of title's keywords frequency across the text that represent
the relevance degree that required, with depending on a lexicon of a particular
field(in this work we choose computer science field). This lexicon is
represented using two different B+ trees one for non-keywords and the other
for candidate keywords, these keywords was stored in a manner that prevent
redundancy of these terms or even sub-terms to provide efficient memory
usage and to minimize the search time.
The proposed system was implemented using Visual Prolog 5.1 and after
testing, it proved to be valuable for finding the degree of relevance between a
text and its title (from point of view of accuracy and search time).