Journal of Techniques

This study expands the original model of theory of planned behavior (TPB) by adding four predictors to the existing model to evaluate travel behaviour in the city of Petaling Jaya in Malaysia. These predictors are: situational factors, trust, novelty seeking, and external influence.Petaling Jaya has witnessed a dramatic growth in terms of population size and geographical importance making it ideal for this study. The study collected research data from employees in Petaling Jaya, Malaysia, resulting in valuable data of 400 participants over the course of three months. Results indicate that attitude,perceived behavioural control, and subjective norm are found to have positive effectson the behavioural intention of using public transport. Furthermore, novelty seeking also has a positive influence on attitude. The three antecedents of trust were found to have an indirect positive effect on commuters’ intention to use public transport via attitude, subjective norm and PBC. Situational factors were found to have an indirect negative significant influence on people’s intention to use public transport through attitude. While external influence was found to have an indirect positive significant influence on people’s intention to use public transport through subjective norm

This study investigates the effects of compression ratio variations (7, 7.5, 8, 8.5 and 9) on the spark ignition engine performance (indicated power ,indicated thermal efficiency ,indicated specific fuel consumption and heat losses) and combustion characteristics (ignition delay ,turbulent flame speed and mass burning) by simulation method for the speeds of (1800, 2400 and 3300) rpm with a spark timing of (-20, -25 and -32.5) deg. for each speed respectively .
The results showed that the compression ratio has a great influence on some parameters of combustion characteristics and engine performance. Where any increase in this ratio increases most combustion characteristics except mass burning rate which is affected only by engine speed and spark timing ,while the power, efficiency and (I.S.F.C) are improved significantly , with a little increasing of heat losses through the combustion chamber walls

The corrosion behavior of gray cast iron in sea water at diverse temperatures (25, 50 and 75) °C and diverse velocity (1, 2 and 3) m/min was actualized. Many specimens were prepared in dimensions of (1.5* 1.5 * 0.3) cm according to ASTM G7-1-31then electrochemical potential state cell was used for corrosion tests, the positive electrode (anode) was signifies the test specimen while the cathode was made from tungsten metals, the voltage was determined by open circuit and associate with the positional of metal in the electrochemical series then voltage was increased + 100 mV, at each 10-mV increasing in the current and determine the corrosion current Sea water (3.5% NaCl in 1 litter distill water) temperature altered after each test then varying the velocity after each test (1, 2 and 3) m/min at stable temperature sea water 25 oC, calculating corrosion rate by using Tafel equation. Another test implemented such as microstructure examination using optical microscope. The results show that the corrosion rate increased with increasing solution temperature this is because of the prevention of oxygen from dissolving in water while the corrosion rate decreases by increasing velocity of sea water. Since the movement of the liquid avoids the formation of sums and ions gathering on cathode electrode where corrosion can simply improve.

In this research, its aim to increase the security level of the mobile systems for the Fourth Generation (4thG), and to study security of images to enhance the information security for users.Long Term Evolution is one of the mobile systems that used inFourth Generation (4thG) cellular networks. Long Term Evolution(LTE) is a modern and newest technology that is emerged to improve the security and service of communication. This work is an attempt to study the LTE security and dealing it with stream cipher algorithm which is called ZUC algorithm . Also, we applied the ZUC algorithm to encrypted image.
MATLAB software ver. 2013a is used in this work for the proposed image algorithm.

This research use the life cycle cost analysis and a detailed cooling, heating and electrical load profiles to determine the initial, running and maintenance costs for evaluation the economic feasibilities of using three different types of central air conditioning systems in a commercial building located in Baghdad city / Iraq, so as to select the best air conditioning system. The systems were modern air conditioning system (variable refrigerant flow), all air conditioning system (package roof top unit) and all water air conditioning system (fan coil unit). The present-worth cost method for lifecycle cost period for fifteen years analysis is applied. The transfer function method was used with hourly analysis program (HAP v4.9) for estimation the cooling and heating loads in each space of the building with adopted the indoor air quality in the design as adequate fresh air per person, acceptable noise level and air quality. The comparison between the different methods for the total cost (during fifteen years) for air conditioning systems showed that the variable refrigerant flow system has lowest total cost compare with other methods used for the period operation, so as the variable refrigerant flow air conditioning system worked into variable cooling and heating load between 0% and 100% of total load.

This study presents the modification for electromagnetic model of the three phase distribution transformer'' D.T'' 400 KVA 11/.416KV,which have properties immersed oil and core type. It was fabricated at Ministry of industry in Baghdad/Iraq."ANSYS11 " was used to analyze this "D.T". The electromagnetic model analysis is used to explain the distribution of magnetic flux density and to calculate the losses of the transformer in case of no load which was 0.2KW and the losses at load was (4.3KW) . The suggested model was compared with practical results which gave a good effect for model results. The modification of this work was done by changing the core material to amorphous steel "Am. St." from silicon steel "Si.St." .The no load losses is (0.08 KW) and the load losses is (4.01KW).