Al-Rafidain Engineering Journal (AREJ)

In this paper, we tried to interrogate measurements and numbers and extrapolated them, through an analytical study,and four relationships that are found that are called the basic equations for the design of the Malqaf, containing four basic units and their repetition, each of which was expressed by a bundle of identical straight lines that represent the equations of a straight line passing through the principle of coordinates, These four identical line bundles relate the size of the room, the size of the Malqaf, its width, depth and height from the roof of the building, and the errors were calculated, so these errors were among the permissible human measurement errors. These relations werea mathematical proof of the straight monotheistic thought on which the Islamic religion is based and on the idea of ​​unity and repetition in Islamic architecture in an innovative mathematical way.

The research presents the site surveying data for per capita indoor water consumption that carried out in Mosul city, Iraq.
 A questionnaire containing over 30 questions was developed to collect a precise information on household characteristics (family size, number of children, income and educational level of house parents), with daily  indoor water consumption, according to the days of the week, taking into consideration water supply continuity, in addition to the built and site area of the house. Over 132 households of standalone, houses with different characteristics were obtained.
The data showed abnormal distribution due to a Non-parametric statistical analysis. Indoor water consumption revealed a positively significant relationship with family size, site area and built area of the house. Whereas, there were a negatively correlation with number of children, monthly income of householder and their educational level, were tabulated, No significant relationship with number of interrupted supply days was observed. Statistical regression analysis elucidated that the educational level of householder followed by family monthly income, family size, the built area and the site area were the crucial weighted factors affecting the indoor water consumption.

Abstract
The present paper dealt with the evalution of quantiy and qualtiy of water treatmetn plants WTPs withen Mosul city. According to the total productivity of WTPs the per capita share of water was 785 L/d, and after subtracting the losses and violation upon the water supply network that reaches upto 50% the per capita portion of water becomes 392 L/d. For the quality of water; the study revealed that there are a segnificant effect of the WTPs processes upon the water quality parameters of the product water comparing with the raw water, and the quality of product water is withen the Iraqi dirnking water spicifications regarding to the parameters taken into account withen the study. This study concentric to the turbidity removal by WTPs because these plants are designed to reduce the turbidity of water to acceptable levels withen the Iraqi specification. turbidity of water is out of the specification in 13% of the samplise with different portions through the WTPs, but the highst was at aldanadan and alsaheroon plants.
Duncn test revealed that there are a significant different betweent the average of the residual turbidity and  between the average of percentage removal of turbidity between WTPs and the worest plant from the residual turbidity are alsaheroon, alghzlani and aldanadan. And the woreste plant from the percent turbidity removal are alaiser aljadeed and alaiser altawsie.

Nitrogen and phosphorus are essential for the growth of micro-organisms used in wastewater treatment. When a treatment system is designed to remove a quantity of nutrients، larger than the ordinary metabolism requirements of bio-cell، the operation is called biological nutrient removal BNR. The BNR system consists of two processes: the biological nitrogen removal and the enhanced biological phosphorus removal (EBPR). There are several arrangements for biological nutrient removal processing. The selection of the suitable treatment scheme depends on the characteristics of the raw wastewater، quality of treated effluent required and the economical consideration. Several studies showed that the A2O system is the most suitable among different configurations because of its simplicity in operation، low oxygen requirements (i.e. low operational cost)، high efficiency of nutrient removal and a good settling characteristics of the sludge produced. A continuously flow laboratory scale of A2O was used in the current study. A raw municipal wastewater from the environmental engineering department is flowing at a rate of 0.6ml/sec. The mean cell residence time was 12 days. The experiments were conducted under three different internal cycle ratios (IR) and three returned activated sludge ratios، The effective sizes of the anaerobic، anoxic and aerobic compartments were 6.4، 8.65 and 17.21 L respectively، The results showed that the percentages of internal cycle ratio have a significant effect on the process of biological removal of nitrates while the percentage of returned activated sludge (RAS) has a significant impact on the biological removal of phosphorus. The A2O system removal efficiency of COD، orthophosphate and ammonia were: 85.7%، 93.5%، and 92.4%، respectively. The effluent quality is within the Iraqi standards with respect to organic and nutrients contents.

The main objective of this study is to investigate the experimentally the coefficient of discharge for three baffle sluice gates and compared with single gate. The channel slope was changed tow times (0, 0.0075). For this purpose three baffle sluice gates were made from fibber class with (1cm) thick, (30cm) wide and (15,25,30)cm height for first, second and third gate respectively. The three gates have been sharp edge from the top and bottom with 2mm thick .The distance between the three parallel baffle gates were changed three times (2, 3.5, 5) cm. The analysis of results showed that discharge coefficient Cd in horizontal channel is larger than its value in inclined channel with direction of flow and the change in space between gates didn^'t cause an important difference between values of discharge coefficient Cd. The values of Cd were between          (0.561 -0.736) for horizontal channel and three gates, while when the channel inclined the values of Cd were between (0.523-0.662) for three gates.