Preferred Language
Articles
/
joe-599
Experimental Study of Optimum Chilled Water Distribution Configuration in Air Conditioning Terminal Unit Using RSM Technique
...Show More Authors

The distribution of chilled water flow rate in terminal unit is an important factor used to evaluate the performance of central air conditioning unit. A prototype of A/C unit has been made, which contains three terminal units with a complete set of accessories (3-way valve, 2-way valve, and sensors) to study the effect of the main parameters, such as total water flow rate and chilled water supply temperature with variable valve opening. In this work, 40 tests were carried out. These tests were in two groups, 20 test for 3-way valve case and 20 test for 2-way valve case. These tests were performed at three levels of valve opening, total water flow rate and water supply temperature according to the design matrices established by Design of Experiment (DOE) software 'version 7' with Response surface methodology (RSM) technique. The model was conducted for each case of total heat rate, then checked statistically for adequacy by Analysis of variance (ANOVA), and found good with 95% confidence level. The results showed that the water supply temperature has a significant effect on the total heat rate of two cases. It was found that the optimum solution for maximum total heat rate and minimum flow deviation represented by standard deviation was obtained at 10°C water supply temperature, 5.5 l/min total water flow rate and 70% valve opening. The total heat rate and standard deviation were (890.249 Watt), (0.000513), respectively in three-way valve case and (743.155 Watt), (0.00277), respectively in two-way valve case. Finally, the predicted and experimental results of total heat rate and standard deviation were in agreement with a maximum error of 6.6 % in three-way valve case and 1.4% in two-way valve case.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jan 01 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Preliminary quality assurance of printgrammetry technique-3D modeling from Google Earth 3D imagery data
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Determination of Cefalexin by Direct (UV- Vis) Spectrophotometer and Indirect(Flame Atomic Absorption) Technique
...Show More Authors

         A new method for the determination of the drug cefalexin in some Pharmaceuticals using (UV-Vis) and  indirect Flame Atomic Absorption Spectrophotometer (FAAS) , Fe III should forms a chelating complex with cefalexin (CEX –Fe III) at pH (1-8) and the best pH for the formation of (CEX –Fe III) chelating complex was (2) .The complex extracted with Methanol  and  Dimethy-Sulphoxide .The mole-ratio method has been used to determine the structure of chelate (CEX - Fe III) and found to be 2:1 LM ( Ligand : Metal.) .

Keywords : Cefalexin , chelating complex.

View Publication Preview PDF
Crossref
Publication Date
Tue Sep 01 2020
Journal Name
Al-khwarizmi Engineering Journal
Pre-Processing and Surface Reconstruction of Points Cloud Based on Chord Angle Algorithm Technique
...Show More Authors

Abstract

Although the rapid development in reverse engineering techniques, 3D laser scanners can be considered the modern technology used to digitize the 3D objects, but some troubles may be associate this process due to the environmental noises and limitation of the used scanners. So, in the present paper a data pre-processing algorithm has been proposed to obtain the necessary geometric features and mathematical representation of scanned object from its point cloud which obtained using 3D laser scanner (Matter and Form) through isolating the noised points. The proposed algorithm based on continuous calculations of chord angle between each adjacent pair of points in point cloud. A MATLAB program has been built t

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sun Feb 24 2019
Journal Name
Iraqi Journal Of Physics
Laser energy effect on the properties of ZnS thin films prepared by PLD technique
...Show More Authors

Zinc sulfide (ZnS) thin films were deposited on glass substrates using pulsed laser deposition technique. The laser used is the Q-switched Nd: YAG laser with 1064nm wavelength and 1Hz pulse repetition rate and varying laser energy 700mJ-1000mJ with 25 pulse. The substrate temperature was kept constant at 100°C. The structural, morphological and optical properties of ZnS thin films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM) and UV-VIS spectrophotometer.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of Iron tungstate oxide films by advanced controlled spray pyrolysis technique
...Show More Authors

For the first time Iron tungstate semiconductor oxides films (FeWO4) was successfully synthesized simply by advanced controlled chemical spray pyrolysis technique, via employed double nozzle instead of single nozzle using tungstic acid and iron nitrate solutions at three different compositions and spray separately at same time on heated silicone (n-type) substrate at 600 °C, followed by annealing treatment for one hour at 500 °C. The crystal structure, microstructure and morphology properties of prepared films were studied by X-ray diffraction analysis (XRD), electron Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) respectively. According to characterization techniques, a material of well-crystallized monoclinic ph

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue May 01 2018
Journal Name
Iop Conference Series: Materials Science And Engineering
Evaluation of Electromagnetic Near-Field Measurement Technique as Non-Destructive Testing for Composite Structures
...Show More Authors

View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Oct 19 2021
Journal Name
Biochem
A Neuro-Fuzzy Technique for the Modeling of β-Glucosidase Activity from Agaricus bisporus
...Show More Authors

This paper proposes a neuro-fuzzy system to model β-glucosidase activity based on the reaction’s pH level and temperature. The developed fuzzy inference system includes two input variables (pH level and temperature) and one output (enzyme activity). The multi-input fuzzy inference system was developed in two stages: first, developing a single input-single output fuzzy inference system for each input variable (pH, temperature) separately, using the robust adaptive network-based fuzzy inference system (ANFIS) approach. The neural network learning techniques were used to tune the membership functions based on previously published experimental data for β-glucosidase. Second, each input’s optimized membership functions from the ANF

... Show More
View Publication
Scopus Crossref
Publication Date
Mon Aug 03 2020
Journal Name
Rawal Medical Journal
Functional outcomes of sandwich reconstruction technique for giant cell tumor around the knee joint
...Show More Authors

Objective: To evaluate the functional outcomes after extended curettage and reconstruction using a combination of bone graft and bone cement (sandwich). Methodology: In this prospective case series 16 skeletally mature patients with primary giant cell tumor around the knee were included. Patients with previous surgically treated, malignant transformation, degenerative knee changes and those presenting with pathological fracture were excluded. The tumor was excised with bone graft filling space beneath the articular cartilage and a block of gel foam was placed over the cortical surface of picked bone graft. Remaining cavity was filled with polymethylmethacrylate cement (sandwich) with or without internal fixation. The func tional evaluation

... Show More
Preview PDF
Scopus
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Solution of Nonlinear High Order Multi-Point Boundary Value Problems By Semi-Analytic Technique
...Show More Authors

In this paper, we present new algorithm for the solution of the nonlinear high order multi-point boundary value problem with suitable multi boundary conditions. The algorithm is based on the semi-analytic technique and the solutions are calculated in the form of a rapid convergent series. It is observed that the method gives more realistic series solution that converges very rapidly in physical problems. Illustrative examples are provided to demonstrate the efficiency and simplicity of the proposed method in solving this type of multi- point boundary value problems.

View Publication Preview PDF
Crossref
Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Studying the optical properties of ( Cr2O3:I ) thin films prepared by spray pyrolysis technique
...Show More Authors

Undoped and Iodine (I)–doped chrome oxide (Cr2O3)thin films have been prepared by chemical spray pyrolysis technique at substrate temperatures(773K) on glass substrate. Absorbance and transmittance spectra have been recorded as a function of wavelength in the range (340-800 nm) in order to study the optical properties such as reflectance, Energy gap of allowed direct transition, extinction coefficient refractive index, and dielectric constant in real and imagery parts all as a function of wavelength. It was found that all the investigated parameters affect by the doping ratios.

View Publication Preview PDF