Preferred Language
Articles
/
alkej-280
Experimental Study of the Performance of Compound Parabolic Concentrating Solar Collector
...Show More Authors

The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 59o, consequently. A significant difference between the instantaneous thermal efficiency of 3.86× CPC (θc=20o) and 2.32× CPC (θc=26o), and between that for 3.61× CPC (θc=26o) and 2.32× CPC (θc=26o). It's noticed that the difference between the instantaneous thermal efficiency of 2.32× CPC (θc=59o) and 2.32× CPC (θc=26o) is small compared with the difference of the first and second cases, the instantaneous thermal efficiency of 2.32× CPC (26o) was higher than those for other three CPCs. The experimental results show that the maximum thermal efficiency of the full 2.32×CPC (26o) is 0.708, the maximum thermal efficiency of the 3.93×CPC (15o), when it's truncated to 3.84× CPC (20o), 3.61× CPC (26o) and 2.32× CPC (59o)  are 0.51, 0.52 and 0.66, respectively. As the concentration ratio decreases from (3.93× to 1×), the thermal efficiency, energy losses and optical efficiency increase from (0.47 to 63), (1.58 to 7.2 K.m2/W) and (0.494 to 0.797), respectively.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Oct 01 2016
Journal Name
Journal Of The College Of Basic Education
EC 80التأثير السمي للمبيد العشبي الكولد توبيك ,على غلاصم سمكة الكمبوزيا هولبروكي Gambusia holbrooki Girard 1859
...Show More Authors

View Publication
Publication Date
Tue Sep 30 2014
Journal Name
مجلة العلوم الاقتصادية والادارية - جامعة بغداد
تحليل الأثر الارتدادي و التفاعلي بين السياسة المالية و النقدية على التوازن الاقتصادي العام (IS-LM)‎
...Show More Authors

يتناول هـذا البحث بالتحليل التفاعل و التنسيق بين السياستين الماليـة و النقديـة و اثر هذا التفاعل و التنسيق على الاستقـرار و النمـو الاقتصـادي، و كيف ان الآثار المالية للسياسة النقدية قد تحفز الإجراءات الخاصة بالسياسة النقدية و معالجة الآثـار الجانبيـة و طبيعـة التفاعل و الارتداد بين إجراءات كلتا السياستين و أثرهما في التـوازن الاقتصـادي العــام، و تم في ثنايا البحث توضيح مسوغات التنسيق و مدى ضرورة ذلك بهد

... Show More
Publication Date
Tue Jul 29 2025
Journal Name
Sciences Journal Of Physical Education
المشكلات النفسية المترتبة على جائحة كوفيد 19 لدى طالبات وتدريسيات جامعة بغداد الممارسات وغير الممارسات للرياضة
...Show More Authors

View Publication Preview PDF
Publication Date
Sun Mar 01 2020
Journal Name
Baghdad Science Journal
Mobile-based Telemedicine Application using SVD and F-XoR Watermarking for Medical Images
...Show More Authors

A medical- service platform is a mobile application through which patients are provided with doctor’s diagnoses based on information gleaned from medical images. The content of these diagnostic results must not be illegitimately altered during transmission and must be returned to the correct patient. In this paper, we present a solution to these problems using blind, reversible, and fragile watermarking based on authentication of the host image. In our proposed algorithm, the binary version of the Bose_Chaudhuri_Hocquengham (BCH) code for patient medical report (PMR) and binary patient medical image (PMI) after fuzzy exclusive or (F-XoR) are used to produce the patient's unique mark using secret sharing schema (SSS). The patient’s un

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
Evaluation Tv- Image Quality for Different Cable Signal Transmission Resistance Based on Contrast Edge Algorithm
...Show More Authors

Some degree of noise is always present in any electronic device that
transmits or receives a signal . For televisions, this signal i has been to s the
broadcast data transmitted over cable-or received at the antenna; for digital
cameras, the signal is the light which hits the camera sensor. At any case, noise
is unavoidable. In this paper, an electronic noise has been generate on
TV-satellite images by using variable resistors connected to the transmitting cable
. The contrast of edges has been determined. This method has been applied by
capturing images from TV-satellite images (Al-arabiya channel) channel with
different resistors. The results show that when increasing resistance always
produced higher noise f

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Using panel data in structural equations with application
...Show More Authors

The non static chain is always the problem of static analysis so that explained some of theoretical work, the properties of statistical regression analysis to lose when using strings in statistic and gives the slope of an imaginary relation under consideration.  chain is not static can become static by adding variable time to the multivariate analysis the factors to remove the general trend as well as variable placebo seasons to remove the effect of seasonal .convert the data to form exponential or logarithmic , in addition to using the difference repeated d is said in this case it integrated class d. Where the research contained in the theoretical side in parts in the first part the research methodology ha

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jan 01 2024
Journal Name
المجلة العراقية للعلوم الاقتصادية
قياس وتحليل تأثير صدمات أسعار النفط الخام على راس المال البشري في العراق للمدة (1970 – 2021)
...Show More Authors

قياس وتحليل تأثير صدمات أسعار النفط الخام على راس المال البشري في العراق للمدة (1970 – 2021)

Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
النجاح الستراتيجي للمنظمــــات على وفــق ابعــــــــــاد القيــــــــــــادة التحويليـــــــــــة: دراســـــــــــة استطلاعيــــــــــــة لعينـــــــــــــة من افراد الهيئـــــــــــة العامــــــــــــة للضرائب
...Show More Authors

In today's world the role of leadership in the control factors of the organization different and advancement, and that the possession of the human ability to the development and creation and innovation varies from one individual to another depending on experience; and levels of performance and intellectual; and his mental and physical and other such factors can create a kind of differentiation between the built humans, and this distinction creates our leaders are able to influence others and have the wisdom and connect active individuals and organizations. as the need for organizations of all sizes and levels of leadership transformation is an urgent need to link the application of the various plans and strategies device which direction

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Laser
PDF Temporal Pulse Compression Using Double Cladding Polarization Maintaining Fiber Nested Mach- Zehnder Interferometer
...Show More Authors

 

Abstract: Narrow laser pulses have been essential sources in optical communication system. High data rate optical communication network system demands compressed laser source with unique optical property. In this work using pulsed duration (9) ns, peak power 1.2297mW, full width half maximum (FWHM) 286 pm, and wavelength center 1546.7 nm as compression laser source. Mach Zehnder interferometer (MZI) is built by considering two ways. First, polarization maintaining fiber (PMF) with 10 cm length is used to connect between laser source and fiber brag grating analysis (FBGA). Second, Nested Mach Zehnder interferometer (NMZI) was designed by using three PMFs with 10 cm length. These three Fibers are splicing to sing

... Show More
View Publication Preview PDF
Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Educational And Psychological Researches
اثر برنامج تعليمي – تعلمي وفقاً لمفاهيم الطاقة المتجددة والنانوتكنولوجي على التنور التكنولوجي عند طلبة قسم الكيمياء
...Show More Authors

The research aims to build an educational program - learning, according to the concepts of renewable energy and nanotechnology And knowledge of its impact on the technological enlightenment when the third phase students in the Department of Chemistry, and to verify the goal and put the researcher null hypothesis the following: No Statistically significant difference at the level (0.05) between the average scores of the experimental group students who are studying material nanotechnology and renewable energy program Altalima- learning and the average score for the control group of students who are studying the same article the usual way in technological enlightenment. The search was limited to the third row in the Department of Chemistry,

... Show More
View Publication Preview PDF