High smoke emissions, nitrogen oxide and particulate matter typically produced by diesel engines. Diminishing the exhausted emissions without doing any significant changes in their mechanical configuration is a challenging subject. Thus, adding hydrogen to the traditional fuel would be the best practical choice to ameliorate diesel engines performance and reduce emissions. The air hydrogen mixer is an essential part of converting the diesel engine to work under dual fuel mode (hydrogen-diesel) without any engine modification. In this study, the Air-hydrogen mixer is developed to get a homogenous mixture for hydrogen with air and a stoichiometric air-fuel ratio according to the speed of the engine. The mixer depends on the balance between the force exerted on the head surface of the valve and the opposite forces (the spring and friction forces) and its relation to decrease and increase the fuel inlet. Computational fluid dynamics (CFD) analysis software was utilised to study the hydrogen and airflow behaviour inside the mixer, established by 3.2 L engine. The Air-hydrogen mixer is examined with different speeds of engine1000, 2000, 3000 and 4000 RPM. Results showed air-hydrogen mixture was homogenous in the mixer. Furthermore, the stoichiometric air-fuel ratio was achieved according to the speed of the engine, the developed mixer of the AIR-Hydrogen mixing process provides high mixing homogeneity and engines with stoichiometric air-fuel ratios, which subsequently contributes to the high levels of efficiency in engine operation. In summary, the current study intends to reduce the emissions of gases and offer a wide range of new alternative fuels usage. While the performance of the diesel engine with the new air-hydrogen mixer needs to be tested practically.
The aim of the present study is to provide the adequate knowledge about the role of time management in facilitate the work requirements for employees of the administrative department at the Ministry of Higher Education and Scientific Research. The research depend on studying four important dimensions which are (time planning, time organization, time direction and time observation). In addition to study other five dimensions which are (new procedures, clear procedures, short procedures, the available information and the simplicity of the methods
used).Questionnaire sheets consist of (38 questions) distributed to (170) employees and (146) sheets only were considered in the study. SPSS program was used
... Show MoreThe field study of this paper focused on the motives for lawyers to use the website
of the Supreme Judicial Council, and the gratifications achieved as a result of its use.
This study sought to achieve a number of goals, including:
1. Monitoring the patterns of lawyers’ use of the website of the Supreme Judicial Council.
2. Determining the forms that lawyers use to interact on the website of the Supreme
Judicial Council.
This study is a descriptive in kind as the researcher relied on the ‘survey method’ in
its study of the external audience (lawyers) using the questionnaire and scale toolThe questionnaire was distributed among a deliberately chosen sample, consisting of
(160) lawyers who used the website of
The study aims to make an in-depth analysis and the financial account components in the Iraqi balance of payments because it reflects the economic center of the country towards outside world, it also helps in making decision about monetary and financial policies, finance and foreign Trade the importance of FDI for Iraq lies as an important sources as wells provides advanced technology and job chances, It also avoids the country negative effects of borrowing processes from abroad . for analyzing direct and indirect foreign investment on the balance of payments and financial account in a period between (2003 to 2015), a community and research sample have been selected, presented in CBI/ Balance of payments. Department,
... Show MoreThe modern teaching methods, and their importance in achieving the desired learning goals for the individual and the society, have been addressed, as it is necessary to develop the methods, ways and strategies used in the process of teaching the intermediate stages in the various fields in general and the field of physical education in particular, the importance of research is the effect of using the strategy of similarities in teaching some basic skills of basketball for students of the second intermediate. As for the problem of research, the researcher mentioned the lack of use of teachers’ strategy method similarities in the educational units because of its importance, and after study and analysis the researcher found it necessary to i
... Show MoreBackground: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes
Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal
... Show MoreTo find out the impact of maternal risk factors on the outcome of pregnancy in Baghdad city. A descriptive purposive study was carried out on 100 postpartum women who had delivered for 1 hr. to 24 hrs. ago . the study sample was selected from three hospitals in Baghdad city ( Baghdad teaching hospital ,Fatima Al-Zahra'a maternity and pediatric teaching hospital and Al-Yarmook teaching hospital),during the period from 25 Jan. to 25 Feb. 2006. The data were collected through the use of questionnaire format reviewing pregnants' records and personal interview and were analyzed by using descriptive and inferential statistical approaches. The finding revealed that maternal pregnancy complications had weak effects on pregnancy outcome , while mate
... Show MoreBackground: Adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. The objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. Material and methods: Forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered full-contoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500ËšC for 8 hours. The specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. The specimens were then randomly divided into four groups (n=10), group I involves
... Show MoreThe purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie
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