Preferred Language
Articles
/
alkej-90
Study the Dissociation Enthalpies for R134a Clathrate Hydrate in Binary and Ternary Systems
...Show More Authors

In the present work the clathrate hydrate dissociation enthalpies of refrigerant R134a+ water system, and R134a + water + salt system were determined. The heat of dissociation of three types of aqueous salts solutions of NaCl, KBr and NaF at three concentrations (0.09, 0.17and 0.26) mol·kg−1 for each salt type, were enthalpy measured. The Clapeyron equation was used tocalculate heat of dissociation of experimental data for binary and ternary system.In order to find the effect of compressibility factor on heat dissociation enthalpy, the study was conducted by using equation of state proposed by Peng and Robinson Stryjek-Vera (PRSV). The obtained results of dissociation enthalpy for binary system were (143.8) kJ.mol-1 without gas compressibility factor (z) and (136.08) kJ.mol-1 with z where the variation between two values was (5.3%). For ternary system (R134a+ water +NaCl) at three concentrations of this salt, the calculated values were in the range of (146.7 - 154.1) kJ.mol-1without z and (138.02-145.14) kJ.mol-1with z where the variation rang between two values was (5.8-5.7) %. The other two types of salts given similar results within (0.886 - 0.129) % deviation rang about NaCl results without z and (0.818-0.149) % deviation rang with z values.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Jan 11 2018
Journal Name
Al-khwarizmi Engineering Journal
Control on a 2-D Wing Flutter Using an Adaptive Nonlinear Neural Controller
...Show More Authors

An adaptive nonlinear neural controller to reduce the nonlinear flutter in 2-D wing is proposed in the paper. The nonlinearities in the system come from the quasi steady aerodynamic model and torsional spring in pitch direction. Time domain simulations are used to examine the dynamic aero elastic instabilities of the system (e.g. the onset of flutter and limit cycle oscillation, LCO). The structure of the controller consists of two models :the modified Elman neural network (MENN) and the feed forward multi-layer Perceptron (MLP). The MENN model is trained with off-line and on-line stages to guarantee that the outputs of the model accurately represent the plunge and pitch motion of the wing and this neural model acts as the identifier. Th

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
تحليل الفجوة بين الواقع الفعلي و متطلبات المواصفة ISO14001: 2015 دراسة حالة في شركة مصافي الوسط / مصفى الدورة
...Show More Authors

يعد نظام الإدارة البيئية ( EMS ) على وفق المواصفة ISO 14001:2015 من الانظمة الإدارية الحديثة والمهمة في وقتنا الحالي، اذ هو أحد أدوات الأدارة البيئية بعّده مدخلاً للمعالجة أو الحد من المخاطر البيئية وآثارها، وبالخصوص الاثار الناجمة من الصناعة النفطية والتي تعد المصدر الرئيس للتلوث البيئي وهدر ونفاذ الموارد الطبيعية. تتجلى مشكلة الدراسة في ضعف عملية تشخيص والحد من مخاطر الج

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 30 2018
Journal Name
Journal Of Engineering
Deep Oxidative Desulfurization of Model fuels by Prepared Nano TiO2 with Phosphotungstic acid
...Show More Authors

In this study, nano TiO2 was prepared with titanium isopropoxide (TTIP) as a resource to titanium oxide. The catalyst was synthesized using phosphotungstic acid (PTA) and, stearyl trimethyl ammonium bromide (STAB) was used as the structure-directing material. Characterization of the product was done by the X-ray diffraction (XRD), X-ray fluorescent spectroscopy (XRF), nitrogen adsorption/desorption measurements, Atomic Force Microscope (AFM) and Fourier transform infrared (FTIR) spectra, were used to characterize the calcined TiO2 nanoparticles by STAB and PWA. The TiO2 nanomaterials were prepared in three crystalline forms (amorphous, anatase, anatase-rutile). The results showed that the

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Thu Apr 28 2022
Journal Name
Iraqi Journal Of Science
Noble Metals/NiO Core- Shell Based Gas Sensors
...Show More Authors

The application of novel core-shell nanostructure composed of Cu, Ag, Au/NiO to improve the sensitivity of pure NiO to H2S gas sensors is demonstrated in this study. The growth of Cu, Ag, Au/NiO core-shell nanostructure is performed by chemical reaction of NiO on metal nanoparticle (Cu, Ag and Au) that prepared by pulsed laser ablation (PLA( technique. This is to form the homogeneous structure of the sensors investigated in this report to assess their sensitivity in terms of H2S detection. These novel H2S gas sensors were evaluated at operating temperatures of 25 °C, 100 °C and at 150 °C. The result reveals the Cu, Ag, Au/NiO core-shell nanostructure present a good sensitivity at low working temperatures compared by pure NiO nanoparti

... Show More
View Publication Preview PDF
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Engineering
Environment Friendly Eco - City
...Show More Authors

The World witnessed over the past few decades a clear change in the urban existence map, where the number of cities' residents has increased and the cities geographic area expanded, also networks of roads and electric power stations were spread. This extraordinary events caused the drawing of a different identity to the world, race with itself in the field of energy and raw materials consumption. Therefore, the research issue individualizes in the lack of available knowledge concerning the subject of environment friendly ecological urban desiging and planning.So the research aims to define the environmentally friendly eco-city' structural elements and to clarify their most important planning and design foundations. To In

... Show More
View Publication Preview PDF
Publication Date
Sat Oct 30 2021
Journal Name
Iraqi Journal Of Science
Spectroscopic Analysis of DC-Nitrogen Plasma Produced using Copper Electrodes
...Show More Authors

      This study shows the effects of copper material electrode, applied voltage, and different pressure values on electrical discharge plasma. The purpose of the work is the application of the spectral analysis method to obtain accurate results of nitrogen plasma parameters. By using the optical emission spectroscopy (OES), many N2 molecular spectra peaks appeared in the range from 300 to 480 nm. Also, some additional peaks were recorded, corresponding to atomic and ionic lines for nitrogen, target material, and hydrogen, in all samples. The electron density (ne) was calculated from the measurement of Stark broadening effect, which was found to decrease with increasing pressure from 0.1 mba

... Show More
View Publication Preview PDF
Scopus (13)
Crossref (3)
Scopus Crossref
Publication Date
Thu Nov 29 2018
Journal Name
Iraqi Journal Of Science
A new Color image Encryption based on multi Chaotic Maps
...Show More Authors

     This paper presents a new RGB image encryption scheme using multi chaotic maps. Encrypting an image is performed via chaotic maps to confirm the properties of secure cipher namely confusion and diffusion are satisfied. Also, the key sequence for encrypting an image is generated using a combination of   1D logistic and Sine chaotic maps. Experimental results and the compassion results indicate that the suggested scheme provides high security against several types of attack, large secret keyspace and highly sensitive.   

View Publication Preview PDF
Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Engineering
Mechanisms of Plant-Correlation Phytoremediation of Al-Daura Iraqi Refinery Wastewater Using Wetland Plant from Tigris River
...Show More Authors

In developing countries, conventional physico-chemical methods are commonly used for removing contaminants. These methods are not efficient and very costly. However, new in site strategy with high treatment efficiency and low operation cost named constructed wetland (CW) has been set. In this study, Phragmites australis was used with free surface batch system to estimate its ability to remediate total
petroleum hydrocarbons (TPH) and chemical oxygen demand (COD) from Al-Daura refinery wastewater. The system operated in semi-batch, thus, new wastewater was weekly added to the plant for 42 days. The results showed high removal percentages (98%) of TPH and (62.3%) for COD. Additionally, Phragmites australis biomass increased significant

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
Fractal Image Compression Using Block Indexing Technique: A Review
...Show More Authors

Fractal image compression depends on representing an image using affine transformations. The main concern for researches in the discipline of fractal image compression (FIC) algorithm is to decrease encoding time needed to compress image data. The basic technique is that each portion of the image is similar to other portions of the same image. In this process, there are many models that were developed. The presence of fractals was initially noticed and handled using Iterated Function System (IFS); that is used for encoding images. In this paper, a review of fractal image compression is discussed with its variants along with other techniques. A summarized review of contributions is achieved to determine the fulfillment of fractal image co

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (1)
Scopus Crossref
Publication Date
Mon Jul 01 2024
Journal Name
المجلة العلمية لعلوم وفنون الرياضة
العلاقة بين طول الذراع وبعض المتغيرات البايوكينماتيكية في سباحة الفراشة (50 متر) لسباحي المنتخب الوطني
...Show More Authors

Competitive swimming is a highly researched area and technological developments have aided advances in the understanding of the biomechanical principles that underpin these elements and govern propulsion. Moreover, those working in the sports field especially in swimming are interested in studying, analyzing, evaluating and developing motor skills by diagnosing the strengths and weaknesses of the skill, and accordingly, coaches and specialists correct these errors. The researchers chose this (Butterfly swimming) and the (arm length) is an important variable because the success of the stroke is greatly dependent on the propulsion generated from the arm pull, and swimmers with a longer arm span have a mechanical advantage with the resulting f

... Show More
View Publication Preview PDF
Crossref