Preferred Language
Articles
/
alkej-311
Experimental Study Using the Passive Solar Chimney for Evaporative Cooling With PCM and CFM as a Thermal Energy Storage
...Show More Authors

 

      In this work, a test room was built in Baghdad city, with (2*1.5*1.5) m3  in dimensions, while the solar chimneys (SC) were designed with aspect ratio (ar) bigger than 12. Test room was supplied by many solar collectors; vertical single side of air pass with ar equals 25, and tilted 45o double side of air passes with ar equals 50 for each pass, both collectors consist of flat thermal energy storage box collector (TESB) that covered by transparent clear acrylic sheet, third type of collector is array of evacuated tubular collectors with thermosyphon in 45o instelled  in the bottom of TESB of vertical SC. The TESB was made from metallic iron sheets as a shell and fuelled by paraffin wax as phase change material (PCM). The PCM supported by copper foam matrix (CFM) to enhance thermal conductivity of wax. When heat is released from TESB to the air, a buoyancy force will be generated in chimney gaps. Then a difference in pressure between inside and outside test room leads to induce the air flow to test room through wet corrugated cellulose pad, where evaporative cooling (EC) occurs. Results of experimental work, that achieved in June, for 12 to24 hour in the test day, refer to effectiveness using EC to decrease the room temperature comparing. The system reduces test room temperature of up to 8.5~9.2 oC in 11:00 am to 3:00 pm and at highest effectiveness of EC, while minimum reduces in temperature of up to 3.5 oC in 8:00pm to 3:00 am. Also, the results showed the affectivity to using the TESB, during the night time for ventilation and EC, with lower effectiveness than from day time. The range of EC effectiveness equals 30.5-37.5 with a natural vent, while The maximum air change per hour (ACH) equals (3.8-6.187), and the maximum mass flow rate is equal to (36.651 kg.hr-1) at experimental evaluation of the system’s discharge coefficient value 0.371.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Dec 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
إيجاد الحل المقبول (الممكن) والأمثل لأنموذج البرمجة الخطية في ظل عدم تحقق شرطّي الإمكانية والأمثلية
...Show More Authors

تعد البرمجة الخطية عاملاً مؤثراً وفعالاً في عملية صنع و إتخاذ القرار عندما تكون الموارد متاحة أو متوفرة لكي تعطي أهدافاً معينة ، وتكمن البرمجة الخطية في حل وتقييم الانشطة أو الفعاليات عند تطبيق إحدى أدواتها وهي الطريقة المبسطة العامة ، التي يكون فيها الحل مقبولاً (ممكناً) ويجب التوصل الى الحل الامثل عندها تسمى بالطريقة المبسطة الاولية أو يكون الحل فيها أمثلاً ويجب التوصل الى الحل الم

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jun 15 2021
Journal Name
Al-academy
Sustainability by recycling palm waste in designing women's belts: وفاء حسن شافعي -مرام زيد الحربي
...Show More Authors

This research contributes to environmental sustainability by recycling natural waste resources in making clothing products. The research aims to employ palm trees waste in designing belts suitable for contemporary women's fashion trends. Both descriptive and applied research approaches were used. Therefore, a collection of belts was designed and implemented. Then, a questionnaire was used to assess the extent to which the implemented belts achieved in sustainability standards using Likert scale. The sample size was 60 women. The data were analyzed using the SPSS program to calculate the arithmetic mean and standard deviation. One of the significant results of the research is the high average scores of the criteria for achieving sustainab

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 19 2018
Journal Name
Arab Science Heritage Journal
مصطلح مصطلح (i3-gal2) في ضوء نصوص مسمارية غير منشورة من عصر سلالة أور الثالثة
...Show More Authors

The verbal formula // i3-gal2 //is a commonly form in the written Sumerian economic texts, starting from the early dynastic period (2900-2372 BC), ending with the Ur III dynasty (2112-2004 BC).  This formula has appeared either without infixes, or accompanied by infixes like / in-da-gal2/,  corresponded in Akkadian the formula: ibaššu ,which is  means "to found, to Storage ", As to the formula / da / come to indicate "to found with, to storage with--).

View Publication Preview PDF
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Educational And Psychological Researches
الكفاءة الانتاجية الداخلية الكمية في كليات الطب – جامعة بغداد (بحث مستل عن رسالة الماجستير الموسومة )
...Show More Authors

The research aims at the following:

- Identifying the level of internal quantity efficiency in Medical colleges, University of Baghdad by determining the level of productivity for one group for the total batch according to sex variable (males and females). Procedures of the study

The researcher used the descriptive and analytical method has been used by following them up enhanced by flow indicators of students for one session  depending on   special statistical data  analyss .

The results are as follows:

 - The Faculty of Medicine were higher productivity scholarships for one year and two years of schooling, as well as the highest in the efficiency of the Faculty o

... Show More
View Publication Preview PDF
Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Physics: Conference Series
Cu (In, Ga) Se2 an absorber layer of photovoltaic devices
...Show More Authors

CIGS nanoink has synthesized from molecular precursors of CuCl, InCl3, GaCl3 and Se metal heat up 240 °C for a half hour in N2-atmosphere to form CIGS nanoink, and then deposited onto substrates of soda-lime glass (SLG). This work focused on CIGS nanocrystals, indicates their synthesis and applications in photovoltaic devices (PVs) as an active light absorber layers. in this work, using spin-coating to deposit CIGS layers (75 mg/ml and 500 nm thickness), without selenization at high temperatures, were obtained up to 1.398 % power conversion efficiency (PCE) at AM 1.5 solar illumination. Structural formations of CIGS chalcopyrite structure were studied by using x ray diffraction XRD. The morphology and composition of CIGS were studied using

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (6)
Scopus Crossref
Publication Date
Mon Mar 23 2020
Journal Name
Journal Of Engineering
Improving Photovoltaic Panel (PV) Efficiency via Two Axis Sun Tracking System
...Show More Authors

In this paper two axis sun tracking method is used to absorb maximum power from the sun's rays on the solar panel via calculating the sun’s altitude and azimuth angles, which describe the solar position on the Iraqi capital Baghdad for the hours 6:00, 7:00, 8:00, 9:00, 12:00, 15:00 and 17:00 per day. The angles were calculated in an average approach within one month, so certain values were determined for each month. The daily energy achieved was calculated for the solar tracking method compared with the fixed tracking method. Designed, modeled and simulated a control circuit consisting of reference position truth table, PI Controller and two servomotors that tracked the sun position to adjust the PV panel perpendicular

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Some electrical properties of PVA:PEG/MnCl2 thin film composites
...Show More Authors

PVA:PEG/MnCl2 composites have been prepared by adding (MnCl2) to the mixture of the poly vinyl alcohol (PVA) and poly ethylene glycol (PEG) with different weight percentages (0, 2, 4, 6, 8 and 10) wt.% by using casting method. The type of charge carriers, concentration (nH) and Hall mobility (μH) have been estimated from Hall measurements and show that the films of all concentration have a negative Hall coefficient. In D.C measurement increase temperature leads to decrease the electrical resistance. The D.C conductivity of the composites increases with the increasing of the concentration of additive particles and temperature. The activation energy decreases for all composites with increasing the concentration of the additive particles.

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Physics: Conference Series
Effect of Nickel Substitution On Structural and Electrical Properties of Hg<sub>0.5</sub>Pb<sub>0.5</sub>Ba<sub>2</sub>Ca<sub>2</sub>Cu<sub>3-y</sub>Ni<sub>y</sub>O<sub>8+δ</sub> Superconductor Composite
...Show More Authors
Abstract<p>six specimens of the Hg<sub>0.5</sub>Pb<sub>0.5</sub>Ba<sub>2</sub>Ca<sub>2</sub>Cu<sub>3-y</sub> <italic>Ni<sub>y</sub> </italic>O<sub>8+δ</sub> (y=0.2,0.4,0.6,0.8,1.0) superconducting compound were prepared by solid state reaction method, with sintering temperature equal to 1123K for 24 hours. The electrical resistivity was examined by the four probe technique, It was found that all the specimens have metallic behavior and increasing the critical temperature with increasing nickel concentration. The optimum critical temperature T<sub>c</sub> was found equal </p> ... Show More
View Publication
Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Mon Jun 20 2022
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
BIRDS OF CONSERVATION CONCERN AT AL-NAJAF DESERT, SOUTHERN DESERT OF IRAQ
...Show More Authors

One eighth of the bird species in the world is considered globally threatened; the avifauna of Iraq comprises 409 species and is considered as the major indicator of the health of Iraq’s biological resources. The Iraqi geography falls into five main regions among which is the desert and semi-desert areas which cover much of the country area. Al-Najaf desert is still one of the poorly known regions from the biodiversity point of view. Birds of conservation concern are detected in Al-Najaf desert during 31 field trips to 20 sites conducted from August 2018 to April 2020, (citing literature records, and personal interviews with locals).The factors caused the bird numbers to decline in Al-Najaf desert include hunting and trapping, logging,

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
أستخدام الضريبة البيئية للحد من الملوثات الناجمة عن عوادم السيارات: أنموذج مقترح للضريبة البيئية في العراق
...Show More Authors

 The researcher tried to show the importance of using environmental taxes as an effective economic factor for reducing contaminators resulting from cars exhausts, and presenting a suggested pattern for  environmental taxes as a nucleus and a starting point for a wider implementing of environmental taxes in Iraq.                                                                      &nbs

... Show More
View Publication Preview PDF