Owing to the energy crisis and pollution problems of today, investigations have concentrated on
decreasing fuel consumption and on lowering the concentration of toxic components in combustion
products by using non-petroleum, renewable, sustainable and non-polluting fuels. While conventional energy sources such as natural gas, oil and coal are non-renewable, alcohol can be coupled to renewable and sustainable energy sources.
In this study, the combustion characteristics of diesel fuel and methanol blends were compared.
The tests were performed at steady state conditions in a four-cylinder DI diesel engine at full load at
1500-rpm engine speed. The experimental results showed that diesel methanol blends provided
12.7% increase in brake-specific fuel consumption due to its lower heating value. The results indicated that methanol may be blended with diesel fuel to be used without any modification on the engine.
The aim of this investigation is to study and analysis the role of governance in the evaluation of the and social performance of the economic units to be addressed through the concept of corporate governance and then to the social performance and its relationship to corporate governance.
The most important obtained results from this research is that the corporate governance of extreme importance, and derive their importance from being an essential tool to contribute to the transparency and fair disclosure of the financial results of economic units in the fight against financial and administrative corruption in economic units, thus providing protection and confidence of all parties, and the evaluating soci
... Show MoreThis study focuses on the behavior of simply supported perforated prestressed concrete rafters (PPCRs) under single midspan monotonic static loading. The experimental program consisted of testing seven specimens; one solid (control) rafter, and six perforated with quadrilateral openings. The main investigated variables are the number and height of the openings. The test findings indicate that, in comparison to the solid rafter, the presence of quadrilateral openings in the PPCRs led to reducing the load capacity by (4.3-36%) and increase the midspan deflection at ultimate by (14.8-33%). Also, increasing the number of concrete posts between openings resulted in increasing the failure load and decreasing the deflection at all stages o
... Show MoreIn this study, the effect of intersecting ribs with inclined ribs on the heat transfer and flow characteristics of a high aspect ratio duct has been numerically investigated. The Relative roughness pitch (P/e) is 10 and the Reynolds number range from 35,700 to 72,800. ANSYS (Fluent-Workbench 18.0) software has been utilized to solve the Reynolds averaged Navier-Stokes (RANS) equations with the Standard k-ε turbulence model. Three ribbed models have been used in this study. Model 1 which is a just inclined ribs, Model 2 which has a single longitudinal rib at the center with inclined ribs and Model 3 which has two longitudinal ribs at the sides. The results showed that the heat transfer rate has been enhanced when the int
... Show More An experimental and computational study is conducted to analyze the thermal performance of heat sinks and to pick up more profound information in this imperative field in the electronic cooling. One important approach to improve the heat transfer on the air-side of the heat exchanger is to adjust the fin geometry. Experiments are conducted to explore the impact of the changing of diverse operational and geometrical parameters on the heat sink thermal
performance. The working fluid used is air. Operational parameters includes: air Reynolds number (from 23597 to 3848.9) and heat flux (from 3954 to 38357 W/m
2 ). Conformational parameters includes: change the direction of air flow and the area of conduct
Resumen
El Ultraísmo es un movimiento literario que comenzó en España a finales de 1918 y continuó hasta el año 1922. Este movimiento, que representó la contribución de España al Vanguardismo literario, que en la primera parte del siglo XX surgió en toda Europa, se desarrolló no tanto a través de los libros, cuanta a través de las revistas literarias de la época.
La creacionista es, sin duda, la escuela que dio a Ultra mayores aportes. Por esta razón, en las literaturas de Vanguardia se funden, y a veces también se confunden, con frecuencia, Ultraísmo y Creacionismo. Los dos movimientos eran como una revo
... Show MoreThis study was carried out to determine the heavy metal accumulation of Juncus rigidus Desfontaines, 1798 from three different regions of the Basrah Province in Southern of Iraq. Specifically, the concentrations of lead, nickel, and cadmium were determined in the roots, culms and leaves of the plant. The results indicated that the highest accumulation of the heavy metal was recorded in lead (Pb) 12.50± 3.58 mg kg-1and then in nickel (< 0.30). The lowest value was recorded for cadmium (< 0.05). As well, lead concentrations in J. rigidus varied in different locations and parts of the plant from undetectable in control to 12.66, 19.33, and 9.80 mg kg-1 in leaves, culm, and roots respective
... Show MoreField experiment conducted to measured Slippage, Effective field capacity, Field Efficiency, Soil Volume Disturbed and Specific Productivity Tillage in silt clay loam soil with depth 18 cm in Baghdad- Iraq. Split – split plot design under randomized complete block design with three replications using Least Significant Design 5 % was used. Three factor used in this experiment included Two types of plows included Chisel and Disk plows which represented main plot , Three Tires Inflation Pressure was second factor included 1.1 ,1.8 and 2.7 Bar, and Three forward speeds of the tillage was third factor included 2.35 , 4.25 and 6.50 km/hr. Result show chisel plow recorded best parameters performance
Three different distribution modules of silicon solar cells in a panel are used in this study . Each module consists of five identical circular silicon solar cells of radius (5cm) and then the total panel areas are identical. The five solar cells are arranged in the panel in different shapes: circular, triangular and rectangular .The efficiency for these three panel distribution are measured indoor and outdoor. The results show that the efficiency is a function of the cells distribution.
Drilling solutions can be considered as an intricate mixture comprising of number of chemical additives which aid specific needs such as controlling the rheological properties and reducing corrosion. Inhibitors are substances that are added in small concentrations to corrosive environment to decrease the corrosion. Their applications can be found in drilling equipments. The effect of adding Zinc Sulphate and Carboxymethyl Cellulose to study their influence on the corrosion of carbon steel in Bentonite mud has been evaluated using Weight Loss Technique. This study focuses on determining rheological properties and corrosion characteristics. Results show CMC and ZnSO4 work as inhibitors when added to the Bentonite with inhibition
... Show MoreIn this paper, a theoretical study to the effect of journal misalignment on the static characteristics of oil filled porous journal bearing when lubricated with couple stress fluid has been carried out.
The analytical model used through this work is for a bearing with isotropic permeability. Considering isotropic permeability the Reynolds' equation for the oil film is modified to include a so – called filter term and the effect of fluid coupled stress. The pressure equation for the porous medium is obtained from Darcy's law and continuity equation. The equation which was used to evaluate the oil film thickness was modified to include the effect of possible misalignment in longitudinal and transverse directions. The governing eq
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