Table of content

Iraqi Journal of Science

المجلة العراقية للعلوم

ISSN: 00672904
Publisher: Baghdad University
Faculty: Science
Language: Arabic and English

This journal is Open Access

About

The Iraqi journal of science is a quarterly specified scientific journal issued by the Faculty of Science at the University of Baghdad. The members of the Editorial Board representing the Departments of Eight Scientific departments, college of science/ Baghdad University and its related units of research, all are professors, scientists with extensive experience and considerable skills in their field of science, as well as an advisory board in support composed of professors and scientists with great reputation in their field of science from other Colleges, universities, or research institutes. The specialty of publication includes the following fields:

1.Pure and Applied Physics.
2.Mathematical Sciences.
3.Computer Science and Information Technology.
4.Science of chemistry.
5.Bio-Science technologies.
6.Earth Sciences, geo-physics, and remote sensing.
7.Astronomy, Space Sciences, and Remote Sensing Unit.
8.Science and Research of tropical area

The visions, goals, and the mechanisms of the Iraqi Journal of Science is to publish scientific research sober in the areas of Applied and Pure Sciences and instructive Iraqi society, scientific research, scientific interest large to contribute to the development of various disciplines, which provides significant support to researchers in all scientific facilities to continue to support the development plans in Iraq.

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Contact info

Baghdad University
College of Science
Baghdad
Iraq
ijs@scbaghdad.edu.iq
07903375590
http://ijs.scbaghdad.edu.iq

Table of content: 2017 volume:58 issue:2B

Article
New Mutations in GyrA Gene of Escherichia Coli Isolated form Iraqi Patients
طفرات جديدة في جين gyrA لبكتريا الايشيريشية القولونية المعزولة من مرضى عراقيين

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Abstract

The present study included a collecting of 165 specimens form different sources, 93 isolates were identified as Escherichia coli depending on morphological and biochemical tests in addition to automated systems such as VITEK 2 and api 20E. All isolates under study developed high resistance toward cefotaxime, ceftazidime, ceftriaxone, and ciprofloxacin estimated by minimum inhibitory concentration. Stool and wound specimens characterized by harbouring the highest resistant isolates in a percentage reached 100% against antibiotics under study. Insignificant differences were found between isolates collected from males and females. Upon using disk displacement method to detect extended spectrum beta lactamases (ESBL), it was found that 37.73% of isolates were ESBL producers. However, stool and urine specimens harboured the highest percentage of producers. The present study findings revealed a presence of efflux pump in 77.5% of tested isolates using cartwheel method. Nevertheless, PCR technique exposed about 85% of isolates harboured acrAB efflux pump gene. Moreover, the results of this study illustrated that all isolates contained gyrA and parC using PCR technique. Accordingly, three isolates were chosen for nucleotide alignment study; one of them is sensitive and the other two are resistant to ciprofloxacin (acrAB free). The results showed a presence of stable and frequent three mutations in the resistant isolates (14 and 3). A transition mutation found in the site 4808116 in which guanine is replaced by adenine. Furthermore, two transversion mutations were located in 4804221 and 4808222 sites. Additionally, a hot spot was detected in the site 4808109.


Article
Epidemiology of Some Parasitic Helminthes in Iraq from 2011 until 2015
وبائية بعض الديدان الطفيلية في العراق من عام 2011 حتى عام 2015

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Abstract

Helminthes are among transmitting pathogens including Ancylostomiasis, Ascariasis, Enterobiasis, Hymenolepiasis, Strongyloidiasis, Taeniasis, Trichuriasis, Schistosomiasis, Echinococcosis. These helminthes have high effect on public health in human population around the world. Iraq is one of the most important endemic areas in the Middle East.The objective of this study is to determine the prevalence of some parasitic helminthes in Iraq from 2011 until 2015. This study was carried out in all Iraqi governorates from 2011until June, 2015.In 2015, the results showed that 6 patients were infected with Ancylostomiasis, 89 patients were infected with Ascariasis, 56206 patients were infected with Enterobiasis, 173patients were infected with Hymenolepiasis, non-patient infected with Strongyloidiasis. 25patients were infected with Taeniasis, 9 cases were infected with Trichuriasis. During the last five years, Iraq was absent of schistosomiasis. Conceding Echinococcosis infection, there were a total of 4769 patients. In 2011, 2012 and 2013 Najaf showed the highest incidence rates of infections 302 patients,277 patients and 215 patients respectively, while Babel, Salaheldin, Wasit, Anbar and Baghdad kerkh governorates had the lowest rate of Echinococcosis infection. In 2014, Thiqar showed the highest incidence rates of Echinococcosis infections (168 patients).In 2015, 81 patients were found in Najaf which reveling the highest incidence rate. Baghdad kerkhdid not record any infections. In conclusion during the time of this study, Iraq successfully eliminate Strongyloidiasis and schistosomiasis, on the other hand Enterobiasis and Echinococcosis represents a health problem in Iraq


Article
Investigation of Microbial Contamination of Primary Schools in Baghdad City
التحري عن الثلوث المايكروبي للمدارس الابتدائية في مدينة بغداد

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Abstract

A microbial contamination of several primary schools (official and private) in Baghdad city was conducted. Sampling was performed in each school from desk, door handle, and hand of students. Out of 113swabs (classes desk, door holder, and students hands ) obtained from ten primary schools, growth wasobserved in 91 samples (80.5%) (for official school 84.6% and 71.4 for private school. The results of recent study revealed that the official schools showed higher contamination levels(130 CFU ) than private ones (90 CFU). Resultes revealed that a total of 12 morphologically different bacterial species were isolated from 62 bacterial isolates,among which gram negative bacteria 40 isolates(64.5%) were higher than gram-positive bacteria 22 isolates( 35.4%). According to the microscopic examination , biochemical tests and API system , the results was showed that staphylococcus epidermidis was the most frequently isolated bacterial species with recovery rate 10 (16 .1%). followed by staphylococcus aureus 8 ( 12.9 %) Escherichia spp7 (11.2%) Escherichia coli7 (11.2%), Enterobacter sakazaki 5(8%), Enterobacter cloacae 5 (8%), Bacillus spp 5(8%), Pseudomonas aeruginosa 4(6.45%), Klebsiella spp 4(6.45%), Klebsiella pneumoniae 3(4.8%), Streptocoocus spp 3(4.8%), Proteus mirabilis 1(1.6%).


Article
Patterns of Phenotypic and Genotypic Resistance to Macrolides, Lincosamides and Streptogramins Group of Antibiotics by Efflux Pump and Enzymatic Modification in Methicillin Resistant Staphylococcus aureus
الانماط المظهرية والوراثية المقاومة لمجموعة مضادات الماكروليدات واللنكوسأمايد والستربتوغرامين في بكتريا Staphylococcus aureus المقاومة للمثيسيلين بألية الضخ خارج الخلية والتحوير الانزيمي

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Abstract

The study was carried out to isolate Staphylococcus aureus isolates from differents clinical samples to detect resistance of isolates to methicillin and detect the phenotypic and genotypic patterns of resistance to macrolides, lincosamides and streptogramins (MLS). The results showed that from 300 clinical sample there were 40 isolate related to S.aureus and there were 38(95)% of isolates were methicillin resistance S.aureus (MRSA). The suscepltibility test showed that there was 55% of isolates were resistance to erythromycin , 35% were resistance to clindamycin and 2.5% had intermediate resistance to the last one . The resistance to streptogramins determined phenotypicallyby the using of vitek 2 compact system,the results showed that there were four types of MLS resistance (iMLS, cMLS, M phenotype and SAB). All isolates were subjected to polymerase chain reaction teqnique in a monoplex pattern to amplify resistance encoding genes msrA, msrB,linA/linA’ and vga .The results showed that 36(90)% of isolates contain msrA(940bp) and msrB(595bp) , 30 (75)% of isolates contain linA/linA’ (323bp) gene while a region of (470bp) of vga gene was not found in any isolate.

Keywords

S. aureus --- MRSA --- iMLSB --- cMLS --- M phenotype --- SAB --- msrA --- msrB --- linA/linA’ --- vga.


Article
Virulence Genes Profile of Escherichia coli Isolated from Urinary Catheterized and Non-Catheterized Patients
الملف الشخصي لعوامل الفوعة لبكتريا Escherichia coli المعزولة من مرضى القثطرة البولية وغير القثطرة

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Abstract

The severity of UTI produced by E. coli is due to the expression of a wide spectrum of virulence factors. In this study the role of E. coli virulence determinants in the pathogenesis of UTI in urinary catheterized and non-catheterized patients has been evaluated. The isolates were recovered from 129 patients admitted to the hospital. Virulence genes of E. coli were detected by polymerase chain reaction analysis for the prevalence of these virulence factors. The targeted genetic determinants were those coding for Type 1 fimbriae, Pyelonephritis-Associated Pili (PAP), Antigen 43 (Ag43), α-Hemolysin and Aerobactin siderophores among the studied isolates. The prevalence of genes fimH, papC, ang43, hlyA and iutA were 88.37%, 72.09%, 18.60%, 51.16% and 79.06% respectively. The fimH gene with 88.37% had a highest prevalence of virulence genes in patients with UTIs. Statistically in the present study, there was no significant difference in the prevalence of genes profiles of E. coli isolates causing UTI in non-catheterized and catheterized patients. However, all the studied strains exhibited 16 virulence gene patterns; among the strains isolated from patients with urinary catheter showed multitude and greatest diversity of genes patterns than strains from non-catheterized patients.


Article
The Inhibition Activity of Silver Nanoparticles Compared with D-Glycin and Imipenem Effect on the Biofilm Formation by Food-origin Salmonella isolates
الفعل التثبيطي لجزيئات النانو فضة مقارنة بفعل الكلايسين والإمبينيم على تكون الغشاء الحياتي لبكتريا السالمونيلا غذائية المنشأ

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Abstract

Since decades silver was depended worldwide as a treatment to a lot of diseases ranging from burn infections, anthrax, and typhoid fever to bacterial conjunctivitis in stillbirth, but its effectiveness against biofilms is still undetermined. Salmonella is a major cause of food poisoning outbreaks especially in the third world countries. Thus, in the present study; the antimicrobial activity of silver nanoparticles (Ag-NPs) against Salmonella enterica biofilm was examined; their activity was compared with amino acid; D-Glycin and imipenem antibiotic. The result of the study revealed that Ag-NPs exhibited considerable antimicrobial property against Salmonella enterica biofilm where the minimum inhibitory concentration (MIC) was found at 50 μg/ml while MIC of D-glycin and imipenem were 50mM and 4µg/ml respectively. The isolates ability to form biofilm was assayed using the tissue culture plate (TCP) assay, all the isolates were biofilm producers but with a different thickness degrees. It was found that both of Ag-NPs and imipenem inhibited Salmonella biofilm formation, but the inhibition by Ag-NPs was more than the antibiotic imipenem, whereas D-Glycin increased the ability of Salmonella isolates to form biofilm.


Article
The effect of Gamma radiation on The Dielectric Properties of SiO2 Ep: TiO2 Ep Nanocomposite
تأثير أشعة كاما على الخصائص العزلية لمتراكبات الايبوكسيTio2; Sio2 النانوية

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Abstract

This research investigates the dielectric properties (impedance, dielectric constant and dielectric loss) of SiO2 Ep :TiO2 Ep nanocomposite over the frequency range of (102-106 Hz ) at room temperature. The dielectric material used is epoxy resin, while nano-sized titanium dioxide (TiO2) with grain size ( 30nm) , oxide silicon (SiO2) with grain size (12nm) in state volume ratio (0,0.05 ,0.1) .The effect of gamma by using (CS137) for period time (17) day was studied Radiation caused decreasing in real and imaginary parts of dielectric constant and impedance .


Article
A Study of some the optical properties for (SnO2) thin films prepared by Sol-Gel method
دراسة بعض الخواص البصرية لغشاء SnO2 المحضر بطريقة التغشية بالسكب

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Abstract

In this research a bilateral tin oxide (SnO2) thin films was prepared by Sol-Gel method, flow coating technique which is considered a simple and cheap technique. The horizontal sample preparation with and without the use of installed, and also with installed to vertical sample. Results of optical spectroscopy that the biggest values of the transmittance T was for horizontal films with an installed, as for the absorbance A was the biggest values of the vertical sample. For the reflectivity R was value in the horizontal films with installed, less than a horizontal films without Sticky as well as for films vertical. The results of the energy gap Eg for that direct allowed and forbidden transitions and for the indirect allowed and forbidden transfers for the studied Samples were also calculated, and they showed that the highest value of Eg was (3.85eV) for the direct forbidden transfers in the horizontal sample with installer, while the lowest value of Eg was (3.65eV) for the indirect allowed transfers without installer. The vertical film with indirect showed the lowest value for the energy gap ever (3.45eV) for the indirect allowed transitions.


Article
Effect of Additives on Impact Strength of Denture Base Resin
تاثير الاضافات على مقاومة الصدمة لقاعدة راتنج طقم الاسنان

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Abstract

This research has studied the effect of addition glass fibers (woven and chopped) and Zirconium oxide Nano-particles (ZrO2) with different weight percent to the conventional poly (methyl methacrylate) (PMMA). The prepared Nano-crystalline ZrO2 powder with particle size of about 95nm was syntheses directly by sol-gel method. The gel dried at 100oC for 1 hour and annelid at 400oC for 3 hours. The conventional acrylic resin prepared with 2:1 powder to liquid ratio to prepare pure sample, composite samples prepared by reinforcing PMMA with woven or chopped glass fiber (8, 12) wt.%, and reinforcing by (1,2,3) wt.% of prepared ZrO2 Nano-powder. The structural tests include: (XRD, AFM, and FTIR). The crystallized phase composition of dried ZrO2 powder after annealing in air at 400oC has been identified by x-ray diffractometry (XRD). The grain size of dried ZrO2 Nano-particles by atomic force microscope (AFM). The impact strength (I.S.) was measured by using Charpy impact test. The mechanical test done in order to compare the impact strength between pure and composite samples. From the result, the reinforcing PMMA with glass fiber in two forms (woven and chopped) improve the impact strength, while increasing of ZrO2 Nano powder loading led to decrease the impact strength.


Article
Near IR Photoconductive Detector Based on f-MWCNTs/Polythiophen Nanocomposite
كاشف التوصيل الضوئي للاشعة تحت الحمراء القريبة باستخدام مركب نانوي من انابيب الكاربون النانوية متعددة الجدران/ بولي ثايوفين بوليمر

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Abstract

Carbon nanotubes are an ideal material for infrared applications due to their excellent electronic and photo electronic properties, suitable band gap, mechanical and chemical stabilities. Functionalised multi-wall carbon nanotubes (f-MWCNTs) were incorporated into polythiophen (PTh) matrix by electro polymerization method. f-MWCNTs/ PTh nanocomposit films were prepared with 5wt% and 10wt% loading ratios of f-MWCNTs in the polymer matrix. The films are deposited on porous silicon nanosurfaces to fabricate photoconductive detectors work in the near IR region. The detectors were illuminated by semiconductor laser diode with peak wavelength of 808 nm radiation power of 300 mW. FTIR spectra assignments verify that the thiophene groups were successfully introduced into the carbon nanotubes. SEM images reflect that the electro polymerization process gives well incorporated for the MWCNTs by PTh polymer. Characteristics of photodetector were improved after cooling the detector. Figure of merit showed a good IR radiation sensitivity and photo response, while the specific detectivity was in order of 109 cm.Hz1/2/W and at for both MWCNTs loading ratios at forward bias voltage 5 Volts. The rise time and fall time of the output signal are about 192 μs and 121μs respectively which consider good values for these types of detectors

Keywords

MWCNT --- Polythiophen --- Nano-composite --- IR --- Detector


Article
Calculations of the Quadrupole Moments for Some Nitrogen Isotopes in p and psd Shell Model Spaces Using Different Effective Charges
حسابات العزوم رباعية القطب لبعض نظائر النيتروجين في p psd- نموذج فضاء القشرة باستعمال شحنات فعالة مختلفة.

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Abstract

The electric quadrupole moments for some nitrogen isotopes (12,14,15,16,18N) are studied by shell model calculations with the proton-neutron formalism. Theoretical calculations performed using the different set of effective charges due to the core polarization effect. The effective charges in the p-shell nuclei are found to be slightly different from those in the sd-shell nuclei. Most of the results we have obtained are underestimated with the measured data for the isotopes considered in this work.


Article
The Theoretical Solving of Intersection Point of the Horizontal and Vertical Gravity Gradients in Order to Estimate the Depth of Causative Source of Gravity Anomaly
الحل النظري لنقطة تقاطع الانحدار الجذبي الافقي والعمودي لتخمين عمق المصدر المسبب للشذوذ الجذبي

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Abstract

The depth of causative source of gravity is one of the most important parameter of gravity investigation. Present study introduces the theoretical solve of the intersection point of the horizontal and vertical gradients of gravity anomaly. Two constants are obtained to estimate the depth of causative source of gravity anomaly, first one is 1.7807 for spherical body and the second is 2.4142 for the horizontal cylinder body. These constants are tested for estimating the depth of three actual cases and good results are obtained. It is believed that the constants derived on theoretical bases are better than those obtained by empirical experimental studies


Article
A Study of Biostratigraphy of Sinjar Formation in selected sections from northern Iraq
دراسة الطباقية الحياتية لتكوين سنجار في مقاطع مختارة من شمال العراق

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Abstract

Late Paleocene –Early Eocene algae and benthic foraminifera were identified from the Sinjar Formation that crop out in three selected section from northern Iraq. The selected sections: (Derbandikhan ,Qara dagh, Wara Mali has been measured in the field and closely sampled to undertake details. A number of (131) samples were collected illustrating all the lithological changes along the sections, The limestone in the studied section is rich in algae and large benthic foraminifera, The investigation of the thin sections allowed us to identify the (47 ) species of foraminifera and (34) species of algae , Five biozones were distinguished for algae which are :a- Amphiroa iraquensis range zone ,b- Trinocladus perplexus range zone ,c- Lithothamnium – Pagodaporella wetzeli –Lithoporella melobesides Assemblage zone ,d- Cymopolia kurdistanensis- parkerella Sp.- Dissocladella deserta - Jania Sp. Assemblage zone, e- Clypeina merienda –Distichoplax biserialis -Mesophyllum Sp,.-Archaeolithothamnium cf dollonii Assemblage zone. Five biozones were distinguished for large benthic foraminifera which are :- a-Cuvillierina sireli – Cuvillierina vallensis - Cibicides nammalensis – Rotalia trochidiformis Assemblage zone ,b-Miscellane miscella –Discocylina varians Assemblage zone , c-Idalina sinjarica –Nummulites globulus –Spherogypsina globula –Somalina Sp.- Alveolina globosa Assemblage zone, d-Orbitolites Sp. - Assilina Sp.- Ovulites Sp.- Cribogoesella Sp, Assemblage zone, e-Opertorbitolites transitorius range zone. The age of this formation is Late Paleocene-Early Eocene in the studied section.


Article
Centralizers on Prime and Semiprime Γ-rings
تمركزات على الحلقات الاولية وشبه اولية من النمط كاما

Authors: Sameer Kadem سمير كاظم
Pages: 917-919
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Abstract

In this paper, we will generalized some results related to centralizer concept on prime and semiprime Γ-rings of characteristic different from 2 .These results relating to some results concerning left centralizer on Γ-rings.


Article
Iris Outer Boundary Localization Based on Leading Edge Technique
إستكشاف الحدود الخارجية لقزحية العين بالإعتماد على تقنية الخط الموجّه

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Abstract

In recent years, the iris biometric occupies a wide interesting when talking about biometric based systems, because it is one of the most accurate biometrics to prove users identities, thus it is providing high security for concerned systems. This research article is showing up an efficient method to detect the outer boundary of the iris, using a new form of leading edge detection technique. This technique is very useful to isolate two regions that have convergent intensity levels in gray scale images, which represents the main issue of iris isolation, because it is difficult to find the border that can separate between the lighter gray background (sclera) and light gray foreground (iris texture). The proposed method tried to find iris radius by seeking in the two iris halves (right and left) circularly, in term of certain angles interval for each half, to avoid the existence of the upper and lower eyelids and eyelashes. After the two radiuses (i.e. for each half) had been determined, the iris final iris radius would be evaluated to the minimum value of them. This method tested on all samples of CASIAv4-Interval dataset, which consist of 2639 samples, captured from 249 individuals, and distributed on 395 classes, the accuracy of the testing was 100% for outer boundary detection.


Article
Genetic Algorithm based Clustering for Intrusion Detection
العنقدة على أساس الخوارزميات الجينية لكشف التسلل

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Abstract

Clustering algorithms have recently gained attention in the related literature since they can help current intrusion detection systems in several aspects. This paper proposes genetic algorithm (GA) based clustering, serving to distinguish patterns incoming from network traffic packets into normal and attack. Two GA based clustering models for solving intrusion detection problem are introduced. The first model coined as GA #1 handles numeric features of the network packet, whereas the second one coined as GA #2 concerns all features of the network packet. Moreover, a new mutation operator directed for binary and symbolic features is proposed. The basic concept of proposed mutation operator depends on the most frequent value of the features using mode operator. The proposed GA-based clustering models are evaluated using Network Security Laboratory-Knowledge Discovery and Data mining (NSL-KDD) benchmark dataset. Also, it is compared with two baseline methods namely k-means and k-prototype to judge their performance and to confirm the value of the obtained clustering structures. The experiments demonstrate the effectiveness of the proposed models for intrusion detection problem in which GA #1 and GA #2 models outperform the two baseline methods in accuracy (Acc), detection rate (DR) and true negative rate (TNR). Moreover, the results prove the positive impact of the proposed mutation operator to enhance the strength of GA#2 model in all evaluation metrics. It successfully attains 6.4, 5.463 and 3.279 percentage of relative improvement in Acc over GA #1 and baseline models respectively.


Article
Object Tracking and matching in a Video Stream based on SURF and Wavelet Transform
تتبع ومطابقة الجسم في سلسلة الفيديو بأستخدام "سيرف" وتحويل المويجة

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Abstract

In computer vision, visual object tracking is a significant task for monitoring applications. Tracking of object type is a matching trouble. In object tracking, one main difficulty is to select features and build models which are convenient for distinguishing and tracing the target. The suggested system for continuous features descriptor and matching in video has three steps. Firstly, apply wavelet transform on image using Haar filter. Secondly interest points were detected from wavelet image using features from accelerated segment test (FAST) corner detection. Thirdly those points were descripted using Speeded Up Robust Features (SURF). The algorithm of Speeded Up Robust Features (SURF) has been employed and implemented for object in video stream tracking and matching. The descriptor of feature in SURF can be operated by minimizing the space of search for potential points of interest inside the scale space image pyramid. The tracked interest points that are resulted are more recurrence and pother free. For dealing with images that contain blurring and rotation, SURF is best. Fast corner detector can be employed along SURF method to build integral images .The integral images can be used to enhance the speed of image matching. The features that are extracted from video images are matched using Manhattan distance measure. Apply the algorithm of FAST corner detection along SURF descriptor of feature; tracking and matching adequacy is better, fast and more efficient than Scale Invariant Feature Transform SIFT descriptor. The experimental outcomes displayed that the time that SURF could be taken for matching is less than the time that SIFT could be taken ,the SURF accuracy depends on number of key-points which are extracted from each frame. SURF key-points are less than SIFT key-points; therefore, SURF key-points could be considered optimal in the process of matching accuracy


Article
Experimental Study of Pulsed Electrical Discharge in Cylindrically-Tipped of Plasma Switch
دراسة تجريبية للتفريغ الكهربائي النبضي في مفتاح البلازما الإسطواني المستدق

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In this research pulse high voltage circuit was used including resistance, inductance and capacitor to achieve an experiment of cylindrically-tipped of plasma switch .The charging voltage of up to 9kV using Rogowski coil and current-shunt resistance (CVR) used to measure pulsed electrical discharge (PED). The current in both self-triggering and third-electrode triggering modes. The pulsed current peaks 4kA and the duration of circuit pulses were recorded between 0.1μs and 0.3μs. The experimental results has shown clearly the inductance effect in the circuit parts in under damped oscillation regarding the value of circuit parts in addition to the distance of the spark gap cylindrically-tipped electrodes during the plasma propagates under air pressure with their circuit impedance. Under the range of experimental states (2-30)Ω nominal impedance ranges were recorded, rely on the gap and circuit parameters.


Article
Methods and Simulations used to Detect Photons from Exoplanets of a Parent Star
الطرق والمحاكاة المستخدمة لتحسس الفوتونات من الكواكب الخارجية حول النجم

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The extrasolar planets in the vicinity of stars are expected to be bright enough and are very difficult to be observed by direct detection. The problem is attributed to the side loops of the star that created due to the telescope diffraction processing. Several methods have been suggested in the literatures are being capable to detect exoplanet at a separation angle of 4λ/D and at a contrast ratio of 10-10. These methods are more than one parameter function and imposing limitations on the inner working distance. New simple method based on a circular aperture combined with a third power Gaussian function is suggested. The parameters of this function are then optimized based on obtaining a minimum inner working distance This method is capable of detecting exoplanet with an angular separation of 4λ/D and a contrast ratio of 10-10 and it is much easier to be implemented practically.

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