This paper presents a numerical simulation for the combined effect of surface roughness and non-Newtonian behavior of the lubricant on the performance of misaligned journal bearing. The modified Reynolds equation to include the effect of non-Newtonian lubricant and bearing surface roughness has been formulated. The model accounts for the lubricant viscosity dependence on temperature and shear rate. In order to make a complete thermo-hydrodynamic analysis (THD) of rough surface misaligned journal bearing lubricated with non-Newtonian lubricant, the modified Reynolds equation coupled with the energy, heat conduction equations, the equation related the viscosity and temperature with appropriate boundary conditions have been solved simultaneously. The performance characteristics of the bearing were presented with different roughness parameter for the pressure, temperature, load carrying capacity, misalignment moment and friction force. The computer program prepared to solve the governing equations of the problem has been verified by comparing the results obtained through this work with that published by different workers. It has been found
that the results are in a good agreement .The results obtained in the present work showed that the surface roughness characteristics of opposing surfaces and its orientation play an important role in affecting the performance parameters of the bearing. It has been shown that the load in rough aligned journal bearing is higher than that in rough misaligned journal bearing for all surface roughness patterns (γ). An increase in load has been calculated and found to be 29.5% for the bearing with moving roughness while it becomes
32% for the bearing with stationary roughness.
In this study NiO - CoO bimetallic catalysts are prepared with two Ni/Co ratios (70:30 and 80: 20) using the precipitation method of nitrate salts. The effects of Ni /Co ratio and preparation methods on the catalyst are analyzed by using different characterization techniques, i.e. atomic absorption (AA) , XRD, surface area and pore volume measurements according to the BET method . The results indicate that the best catalyst is the one containing the percentage of Ni :Co ( 70 : 30 ). Experiments indicate that the optimal conditions to prepare catalyst are stirring for three hours at a temperature of 60oC of the preparation , pH= (8-9) , calcination temperature at 400oC for two hours
... Show MoreTests were performed on asphalt concrete specimens with (101.6 mm in diameter and 101.6 mm in height), and the results were implemented for calculating permanent deformation and resilient modulus under repeated compressive stress with different levels of stresses (0.068, 0.138 and 0.206) MPa at 40 ºC. Two types of additives namely (carbon black-asphalt) and (SBR-asphalt) were tried as rejuvenators with three percentages of (0.5, 1 and 1.5) % by weight of asphalt cement along with two ratios of AC (1 and 2) % have been implemented as rejuvenator and blended with the reclaimed asphalt concrete. Aged materials were obtained from the site. 100% Reclaimed Asphalt Pavement material from the reclaimed mixture is implemented. A
... Show More: Clobetasol propionate (CP) is a potent corticosteroid used for skin conditions but often causes side effects due its systemic absorption. To improve its solubility and reduce it side effects (like skin irritation, skin atrophy, hypopigmentation and steroidal acne), Microsponge (Msg) has been employed as a unique three-dimensional particle that can encapsulate hydrophilic and lipophilic drugs. This study aims to develop and evaluate CP Msg-loaded hydrogels. Two Clobetasol-loaded ethylcellulose-based Msg formulas were prepared using the quasi-emulsion solvent diffusion method, then they were incorporated into Carbopol hydrogel. Two ratios of Carbopol 940 (1% and 1.5% w/w) were used. The prepared hydrogel were assessed for appearance, pH, dr
... Show MoreThe research dealt with a topic that has been practiced and transmitted news in satellite channels in recent years a lot. That is to say the role of satellite channels in the culture of a protest. In general, this study aims to reach to know the extent of the impact of television, especially the impact of the programs that bear the contents of protest and remonstration on the public; and what can be resulted out of these programs as cognitive, emotional and behavioral effects as a result of the individual's exposure to these programs and their impact from the culture of pretense. In addition to that, the research was interested in explaining the role of Iraqi satellite channels in developing and cultivating such culture; and following up
... Show MoreThis paper presents L1-adaptive controller for controlling uncertain parameters and time-varying unknown parameters to control the position of a DC servomotor. For the purpose of comparison, the effectiveness of L1-adaptive controller for position control of studied servomotor has been examined and compared with another adaptive controller; Model Reference Adaptive Controller (MRAC). Robustness of both L1-adaptive controller and model reference adaptive controller to different input reference signals and different structures of uncertainty were studied. Three different types of input signals are taken into account; ramp, step and sinusoidal. The L1-adaptive controller ensured uniformly bounded
... Show MoreThis study involves the synthesis of a new class of silicon polymers, designated as P1-P7, derived from dichlorodimethylsilane (DCDMS) in combination with various organic compounds (Schiff bases prepared from different amines and appropriate aldehydes or ketones) [I-V] through condensation polymerization. The structures of all monomers and polymers were characterization by FTIR and 1HNMR spectroscopy (for some polymers). The results of thermogravimetric analysis (TGA) and differential scanning calorimetry DSC test show stable thermal behaviour. Polymers with a higher concentration of aromatic rings in their repeating structural units exhibited a higher temperature for weight loss, indicating increased thermal stability. Thermal meas
... Show MoreThis study was carried out to find out the effect of germination of broad beans and chickpeas seeds for different periods on their antinutritional factors content ( Trypsin inhibitor and Phytic acid ) and the chemical constituents of germination seeds compared with the control samples (ungerminated seeds) . The results indicated asignificant increase (P<0.05) in crude protein content as germination period proceeded.The highest values of 28.0% and 24.0% were reached on the sixth and fourth day for germinated broad beans and chickpeas respectively, The intial values were 25.6% and 23.5% for control samples, respectively. The content of raffinose,stachyose and verbascose were reduced as germination period proceeded, Stachyose and verbascose we
... Show MoreThe aim of this work is to study the histological and histochemical structure of the Harderian gland in indigenous pigeons. Samples were obtained from 10 males and 10 females of adult healthy pigeons. Hematoxylin and eosin, Alcian blue (pH 2.5), periodic acid-Schiff and promo phenol blue, stains were used for paraffin section examination. The gland was teardrop like in shape, light brown to pink in color, capsulated with thin connective tissue. It was multilobular compound acinotubular in structure and lined by columnar epithelial cells. Lymphocyte, plasma cells and plasma cells with Russell bodies were present underneath the epithelia of central collecting duct and around the secretory unite. Histochemically; the
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