In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant
... Show MoreDiffraction patterns formed by a ferronematic sample, which contains 4-(trans-4-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT) liquid crystal doped with Fe3O4 rodlike magnetic nanoparticles, was studied. The studied mixture can be applicated as a liquid magnetic switch. The diffraction patterns were observed from the micro-lines scribed on the polymer layer, which was contained by the liquid crystal mixture cell, with dimensions of 4 nm for depth and 0.32 µm for width and 5000 line per 1 mm2 in the case of absence and presence of the DC magnetic field. From the experimental results, it was observed that the application of the magnetic field caused more than 17% expansion in the diffraction patterns a
... Show MoreThe purpose of this research is to investigate the impact of corrosive environment (corrosive ferric chloride of 1, 2, 5, 6% wt. at room temperature), immersion period of (48, 72, 96, 120, 144 hours), and surface roughness on pitting corrosion characteristics and use the data to build an artificial neural network and test its ability to predict the depth and intensity of pitting corrosion in a variety of conditions. Pit density and depth were calculated using a pitting corrosion test on carbon steel (C-4130). Pitting corrosion experimental tests were used to develop artificial neural network (ANN) models for predicting pitting corrosion characteristics. It was found that artificial neural network models were shown to be
... Show MoreThe research stems from its goal of identifying the impact of visual management on the strategic acceleration of business organizations and the state of this effect through the knowledge embedding in the Iraqi oil companies. The oil sector was tested, represented by (3) oil companies, and a sample of (151) individuals who participated in activating the visual management, distributed in higher management levels. The research relied on the descriptiveanalytical approach and the questionnaire was a main tool for collecting data and information. The results showed that visual management positively affects strategic acceleration. Moreover, This effect is amplified by the mediating role played by Embedding Knowledge.
This study aims at suggesting flow as a strategy for training female EFL student-teachers in the teaching training course and finding out the effect of this strategy on their performance and their flow state. The training course syllabuses will be constructed according to the flow nine factors and the teaching skills. The measurement tools are the student-teacher performance checklist that has already been used by the department of English language and SHORT Flow State Scale (S FSS-2). The study population is represented with the (60) female student-teachers/ fourth stage/ evening studies at theEnglish department /college of education for women/the University of Baghdad. The study is used the experimental design in that (30) of the student-
... Show MoreThe main object of this article is to study and introduce a subclass of meromorphic univalent functions with fixed second positive defined by q-differed operator. Coefficient bounds, distortion and Growth theorems, and various are the obtained results.
The paper presents research results of the vibration transmitted from the steering wheel of the
tractor with a 2-wheel drive to the driver’s hands. The vibration measurements were carried out on the
tractor randomly chosen from the collage of agriculture / university of Baghdad. Before testing the
tractor was examined and adjusted following the producer’s recommendations. The vibration levels
were measured during the operation tillage at idling and at full load .The field was 3١٫٧ m above level
sea. Soil was treated at soil constant moisture (1٧-20 %) with depth of plowing (١٧ cm). During
operation the weather temperature was measured (15 C) and humidity was ( 27 % ) The vibration level
on the steering whee