AL-Rafidain Engineering Journal (AREJ)

The re-use of the demolished parts of buildings is considered as an important factor of conserving natural sources and minimizing its consumption, this may be taken as a good development pattern, which leads to compatibility between economical savings and an environmental and social consideration.
Development in this sense not only aims at improving production but also takes into account the abiding by the production rules in considering the available sources, its cost, and its overall effect on environmental and social values. To carry out this research work a number of concrete mixes were prepared using different ratios the specimen then tested the outcome of the crushed concrete specimens were then used as coarse aggregate to constitute new concrete mixes of similar ratios for studying the mechanical properties of those new mixes and comparing then with the original mixes.
The results indicated clearly the possibilities of using recycled destroyed concrete as aggregates also the results showed a reduction in the compressive strength and an increase in tensile strength. Finally a mix design procedure is given foe the future design of any mix using crushed recycled concrete as an aggregate.

In this investigation, two plastomers polymer types namely: polyethylene (PE)
and polypropylene (PP) were used to modify asphalt cement. Nine different blends
including conventional mixture were subjected to binder testing such as rheological
tests before and after aging, as well as to some other tests related to the uniformity of
the system. Marshall stability, Marshall Quotient, static tensile strength, tensile strength
ratio, static compressive strength and index of retained strength were carried out on the
stone mastic asphalt (SMA) mixtures. Research results indicate that the addition of
these polymers enhance the unaged and aged rheological properties of base binder. The
results also indicated that the modified binders are complying with the ASTM D491
specifications for asphalt used in waterproofing applications. As well as, the SMA
mixtures containing such binders can satisfy the performance requirement of hightemperature
and much rain zone.

In this paper, a laboratory plant was constructed and operated in order to assess the effect of stages; detention times and depth of filter on the performance of the upflow anaerobic biological filter that treating domestic grey water. The experimental plant was consisted of two upflow anaerobic filters; the first one operates with a single stage, while the second one was with two stages. Crushed gravels were used as a medium for growing the biological organisms. The two filters were worked simultaneously in continuous flow regime at hydraulic detention times of 12, 18 and 24 hours using greywater samples with COD concentration between 190-350 mg/l. The results showed that the two stages filter was more efficient than the single stage filter. The COD and BOD removals were (55.5, 62.7, 75.3)% and (57.2, 67.4, 78.2)% for the detention times of (12, 18 and 24) hours respectively. While the COD and BOD removals were (67.7, 54.8, 39.1)% and (73.2, 60.5, 44.8)% for the first filter and at the same detention times respectively. The two filters were also efficient in removing the suspended solids. Increasing depth of filter has a little influence on the performance efficiency. Depth of (0.3) m was considered the most effective height by which the quickest COD removal is performed.

This research presents a laboratory study on the influence of different compactive
efforts, curing and soaking periods at no-delayed and up to 4-hrs compaction delay
periods on compaction, strength and swelling characteristics of untreated and 3%, 5%
and 8% by dry weight of lime-treated Semeel soil.
The results of the tests without and with compaction delay of lime-treated soil
show that for both of standard and modified compactive efforts, as the lime content %
increases the Maximum Dry Density (MDD) decreases while the Optimum Moisture
Content (OMC) increases. The decrease in MDD is occurred due to alteration of the
material's gradation as a result of the flocculation and agglomeration of the soil
particles upon lime addition. Whereas the increase in OMC is mainly referred to the
more water required for the hydration of lime and cation exchange. It has been found
that as the compaction delay period increases, the strength properties of lime-treated
soil decrease for unsoaked and soaked conditions. This loss in strength therefore needs
to be considered in design and construction and the durability of the UCS specimens
should be assessed by evaluating their resistance to strength loss after 7-days curing
followed by 4-days soaking. The swelling characteristics measured on remolded soil
samples at no compaction delay show that Semeel soil is classified as highly expansive
soil. While, at small lime contents %, as the compaction delay increases, swell percent and swelling pressure values are slightly increased from that at no compaction delay.

The performance of irrigation systems can be evaluated by criteria which show the efficient use of on-farm water distribution. The different distribution of infiltration depths in the soil may give the same value of application uniformity coefficient; therefore the present study considered the distribution uniformity coefficient of the useful infiltration depths in the root zone as part of the evaluation criteria. The considered criteria was expressed as a function of both application adequacy and the application uniformity of infiltration depths. The derived function is applicable for linear and natural distribution of infiltration depths.

The Digital Differential Analyzer (DDA) is normally used to efficiently compute
the pixels (picture elements) for a straight line segment which can be used to represent
it in a frame buffer or image memory. The calculated integer values of x and y for each
pixel are used to address the memory while the color or intensity of the line segment
presents the data to memory. The pixels in the frame buffer can then be read in a
synchronized manner, while scanning the screen, and displayed on the computer
monitor to show the straight line. This paper presents a new Digital Differential
Analyzer as a three dimension (3D) version of the traditional (2D) one. There is a need
to the 3D-DDA for the solution of the hidden surface problem in the image space when
using depth or Z buffer method in the field of 3D computer graphics. A hardware
implementation of the 3D-DDA is accomplished for the real time applications.

The University of Mosul has recently witnessed a construction of several departments, administrative buildings and lecture halls which may suffer after occupation some environmental or functional problems that require deep studies and researches to diagnose those problems, Hence comes the importance of post occupancy evaluation studies of those buildings as an integral part of the planning , design and construction processes to explore what is positive and negative in the design process , and get benefit from such researches to adopt the positives to enrich the design process and stand on the negatives and their causes to find an appropriate solutions and avoid repeating them in the design of future buildings.
The problems stemming from the indoor environmental quality in the lecture halls comes at the front of these negatives and in particular the daylight and the use of it to enriches the indoor environment and it is supportive impact on students and lecturers performance and psychological health on one hand and the rational consumption of energy expended on artificial lighting on the other.
This study focuses on the post occupancy evaluation of daylighting in the lecture halls at the new buildings of the University of Mosul, and the college of Electronic Engineering has been chosen as a case study because the adoption of one typical design to all of its four departments and replicated in other locations. The study reveals a deficiency of utilization of daylight as a design factor to provide visual comfort for the occupants of these buildings through the cognitive and realistic measurements adopted for this study.

Scaling factor tuning is one of the most used method to enhance the performance of a fuzzy controller. This paper presents two intelligent tuning strategies to tune this factor. In the first strategy, a supervisor fuzzy controller SFC was designed to continuously adjust, on line, the scaling factor of the basic fuzzy controller BFC based on the error and change of error signals. In the second strategy, a neural network NN is used to do this task. Performance of the tuning strategies are compared with corresponding conventional fuzzy controller in terms of several performance measures such as steady state error, settling time, rising time, and peak overshoot. Simulation results show that SFC performance is better. The system implementation and tests are carried out using LabVIEW (V 8.2).

Geometry is presented as one of the concepts which has been employed as a design tool for creating architectural ideas in the design process throughout architectural history, as well as providing order and creating form intentionly. The importance of geometry has emerged, because it is considered the single most common determinant or characteristic in buildings. The paper discusses the importance of this concept and its employment as a formative idea during architectural history.
Thus the objectives of the paper and its problem have been formed by building theoretical framework consisting of one main item of detailed theoretical field as the following: (procedures of creating architectural ideas by employing geometry which is, in term connected by two primary generators; geometric planes and solids with geometric fields or grids), which specifies procedures of employing geometry in creating architectural ideas in different architectural trends, firstly, then the application of this item on the products of three architects: Meier , Eisenman and Graves from the twenties Revivalism trend of the 20th century, secondly, Finally, concluding procedures and paradigms, which had been employed by architects of this trend in creating ideas, thirdly.
Conclusions have been declared, concentration on the concept known as dynamic geometry which is based on a geometric order depending on the combination of both planes and solids with geometric fields, and the employment of both regular and unique free forms, throughout design systemization in making architecture, based on the dynamism of traditional geometric order, depending on selected design relations of formal elisions in the form of dynamic modifications and of grid compositions. Thus, dynamism or movement can be added as a primary principle to the different architecture design principles.

This paper investigate the effect of distance on the Gaussian Mixture Models (GMM) for
text dependent speaker identification. Three stages are used for three different distances from
the microphone (1m, 2m, and 3m). The set of feature extraction used here include Mel
frequency cepstral coefficient (MFCC), Bark frequency cepstral coefficient (BFCC) and
linear predictive cepstral coefficient (LPCC). These features are obtained from 20 speakers
(10 adults and 10 children) ;all spoke five Arabic words in 5 seconds. The set of classification
includes two types GMM and multilayer perceptron neural network (MLP). Total results
show that MFCC has the best performance in feature extraction, and GMM has better
recognition than MLP as total recognition in GMM is 93.15% and recognition in MLP is
88.06%.The results show also that the recognition rate decreases from 93.15% to 80.82% as
the distance is increased from 1m to 3m.

This paper deals with real time DC motor speed control, using the low-cost new generation TMS320LF2812 digital signal processor (DSP). An optimal control algorithm which can be realized through event manager (EV) module of the DSP is proposed. According to the error signal DSP processor will change the duty cycle of the PWM (which can be named mark-space ratio). The comparison between two signals (reference and actual speed) in addition to the PWM technique are included in a C++ language program. Code composer studio (CCS) is used to load and run the program to achieve real time control. Theoretically Matlab/Simulink software was used for simulation the proposed circuit before implementation. A PID controller is designed using MATLAB to generate a set of coefficients associated with the desired controller characteristics.

This paper presents an experimental investigation of the thermal performances of a forced draft counter flow wet cooling tower by using two filled , the first one is made locally from the galvanized packing have a cross-sectional area of (0.3m * 0.3m) with a height of 0.5m and consists of six galvanized sheets having a zigzag form disposed by metallic vertical grids in parallel with a sectional test. The second is made from corrugated plastic with the same cross-sectional area . In present work the effect of each of the air and water flow rates on the cooling water section as well as the tower characteristic, heat rejected and the Cooling range for different inlet water temperatures were studied . From the experimental readings obtained we found that the temperature of inlet hot water to the cooling tower effected in the tower performance concerning amount of heat rejected and the Cooling range . In addition , the experimental result showed that the tower Characteristic increases by using packing made from galvanized about 15% comparing with plastic packing at the same operation conditions .

The design of the present radio direction finder is based on amplitude comparison to find the angle of arrival (AOA) of the received signal by eight antennas circularly distributed. The characteristics of the signal are specified to provide the identification of the source in addition to the direction. The equation of (AOA) was derived by taking the ratio of signal amplitudes between each two adjacent antennas due to their associated AOA over (360) direction .The database for source identification is included also. A simple design by using detectors to detect the pulse and digital signals was used. A personal computer is used to satisfy the principle of operation. This facility make the system operate on a wide band of frequency about (2-18) GHz. This system is suitable for detection of radar signals and digital transmitter signals such as base stations and mobile stations.

To study the effect of crest shape on the performance of rectangular side weirs, one hundred and four side weir models were tested, eight of them were for sharp crest and ninety six for rounded crest. For each set of rounded crest models, the radius of crest was changed four times and for each radius, the height of the side weir was varied four times. A total of nine hundred thirty four tests were conducted on these models. For all models of different crest shapes, it was found that the average energy difference between two ends of the side weir is very small and less than one percent which can be ignored. The variation of discharge coefficient (CM) with upstream Froude number (Fr1) was found to be linear. The correlation between (CM) and ratio of upstream water depth to weir height ( h1/p ) was found to be linear. The variation of (CM) with the ratio of upstream head above crest to crest radius (h1/r) was also found linear. A simple power empirical expression was obtained for the combined effect of (Fr1) and (h1/p) on (CM) for free flow over sharp crest side weirs with high correlation coefficient. Three simple power empirical expressions were obtained for the variation of (CM) with (Fr1), (h1/p) and (h1/r) for the free flow over inside semicircular, outside semicircular and circular crest shapes with high correlation coefficients. From the hydraulic performance, it was found that small weir heights gave higher performance for all crest shapes. The highest performance of inside semicircular crest was found for crest radius (r) =3.15cm, the highest performance of outside semicircular crest was found for (r) =3.75cm, while, the highest performance of circular crest was found for (r) =2.5cm and (r/p) =0.25.

Numerical study has been conducted to investigate natural convection heat
transfer in a square porous cavity with partial active vertical walls. The left vertical
side wall is partially heated and the right side wall is partially cooled. Depending on the
positions of the hot and cold parts, nine cases have been considered in this investigation.
Flow and heat transfer characteristics for all cases have been studied for range of
Rayleigh number 50 ≤ Ram ≤ 500. The governing equations are solved numerically
with aid of the finite difference technique and Gauss – Siedel method. Numerical
results showed that there are significant changes in the flow and temperature fields and
the rate of heat transfer due to the change of the positions of hot-cold parts. Also, they
showed that the maximum heat transfer occurs for the Lower-Upper arrangement,
while the minimum heat transfer occurs for the Upper-Lower arrangement. A
correlation between Nu and Ram proposed for each one of the nine cases.