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Successful construction projects are those to be completed within the planned time, cost and quality, in addition to minimizing waste, pollution and energy consumption. It is believed that adopting lean principles in the construction industry can help a lot in achieving these goals. This research aims at studying the benefits, obstacles and readiness to adopt lean construction in Iraq and the actions needed. A questionnaire was designed based on extensive review of relevant literature and then directed to (123) professionals involved in the Iraqi construction industry. The results were statistically analyzed and tested and found to be valid and reliable. Contradictions of very few aspects were then discussed and clarified through direct interviews with (10%) of the questionnaire respondents . The research revealed that the Iraqi construction industry is in need of all potential benefits that lean construction can provide through value maximization and using modern construction techniques. The research also revealed that the main obstacles are lack of expertise, skills, awareness and knowledge in lean principles and poor culture related to waste identification and control. Concerning the readiness success factors, more emphasis was made to the integration of design, manufacture and construction and life-cycle engineering. Finally, proactive actions were suggested on national and institutional scales taking into account that the major role to shift to lean construction rests with the government and the construction sector leaders. Keywords: Lean Thinking, Lean Production, Lean Construction, Construction Industry, Construction Projects

The shear strength of soil is one of the most important soil properties that should be identified before any foundation design. The presence of gypseous soil exacerbates foundation problems. In this research, an approach to forecasting shear strength parameters of gypseous soils based on basic soil properties was created using Artificial Neural Networks. Two models were built to forecast the cohesion and the angle of internal friction. Nine basic soil properties were used as inputs to both models for they were considered to have the most significant impact on soil shear strength, namely: depth, gypsum content, passing sieve no.200, liquid limit, plastic limit, plasticity index, water content, dry unit weight, and initial voids ratio. Multi-layer perceptron training by the backpropagation algorithm was used in creating the network. It was found that both models can predict shear strength parameters for gypseous soils with good reliability. Sensitivity analysis of the first model indicated that dry unit weight and plasticity index have the most significant effect on the predicted cohesion. While in the second model, the results indicated that the gypsum content and plasticity index have the most significant effect on the predicted angle of internal friction.

In this paper, the effect of footing shape resting on dry sand when subjected to machine dynamic loading is experimentally investigated. A laboratory set-up was prepared to simulate the case at different operating frequencies. Nine models were tested to examine the effects of the combinations of two parameters, including different frequencies of (0.5, 1, and 2 Hz) and different footing shapes (circular, square and rectangular). The tests were conducted under a load amplitude of (0.25 ton) using sand with medium and dense relative densities corresponding to (R.D. = 50% and 80%) having unit weights of (17.04 and 17.96 kN/m3) respectively. A shaft encoder and a vibration meter were used to measure the strain and amplitude displacement, while the stress in the soil at different depths was measured using flexible pressure sensors. It was found that the shape of footing has a considerable influence on the bearing capacity of the supporting soil under dynamic loading. For instance, the strain of dry sand under a circular footing was nearly (41%) higher, the amplitude displacement was nearly (17%) higher, and stress was nearly (12%) higher than square and rectangular footings, under the same conditions.

Experimental model was done for pile model of L / D = 25 installed into a laminar shear box contains different saturation soil densities (loose and dense sand) to evaluate the variation of pore water pressure before and after apply seismic loading. Two pore water pressure transducers placed at position near the middle and bottom of pile model to evaluate the pore water pressure during pullout tests. Seismic loading applied by uniaxial shaking table device, while the pullout tests were conducted through pullout device. The results of changing pore water pressure showed that the variation of pore water pressure near the bottom of pile is more than variation near the middle of pile in all tests. The variation of pore water pressure after apply seismic loading is more than the variation before apply seismic loading near the middle of pile and near the bottom of pile and in loose and dense sand. Variation of pore water pressure after apply seismic loading and uplift force is less than the variation after apply seismic loading in loose sand at middle and bottom of pile.

In recent decades, Iraq has witnessed several military operations. This has led to huge damages to the infrastructure of some main cities. The traditional construction methods seem not to be able to fulfill the rapid reconstruction works needed, while prefabricated building systems seem to be promising. This paper aims at evaluating the possibilities of using prefabrication systems for schools building as a pilot study for wider adoption. An extensive literature review was carried out to identify the features of construction prefabrication and its requirements. Then a thorough investigation of the possibilities of adopting this approach in Iraq and the major expected obstacles was carried out. A questionnaire survey has been conducted with (96) stakeholders who have experience in prefabricated building projects. The results showed that the highest rating of benefits went to time and productivity, while the highest rating of obstacles went to lack of government support. Therefore the top proposed action included the adoption of a clear governmental strategy for change. Finally, the respondents agreed that school building is the most suitable type of projects to start with.

The purpose of the current study is to investigate the impact of novel coronavirus disease (COVID-19) pandemic on the mental health of people living in Bangladesh. Data required for conducting the study were collected from 1000 respondents of Bangladesh especially in reference to Dhaka and Mymensingh districts through serving a structured questionnaire. The sample size was selected by using convenient sampling technique. DASS-21 was used to assess the mental health indicated by level of depression, anxiety and stress among the target respondents. The study found that level of depression; anxiety and stress differ in accordance with the gender, age, marital status, education, employment and professional status. The research result showed that, there is significant difference among gender, age, marital status, educational qualification and professional status in regard to depression, anxiety and stress level whereas there is no significant difference among employment status in regard to depression, anxiety and stress level of the respondents.

This paper focuses on the response of circular machine foundation resting on different soils (sand and clay) through studying the variation of soil shear strength parameters and strain with the number of cycles. The objective of the current study is to explore the results related to the parameters of the dynamic load (number of loading cycles and frequency of load) related to the circular footing of a machine on the dynamic shear strength parameters (for sand soil (ϕ˚dyn) and for clay soil (Cudyn)) in addition to the amplitude strain foundation. A special setup was designed and manufactured to simulate the vertical vibration of a circular machine foundation. A steel circular machine foundation with a diameter of 150 mm was used to represent the footing. A total of 6 cases were examined to take into account the effects of different parameters including different frequencies (0.5, 1, and 2 Hz); state of sand (medium and dense) which corresponded to relative densities of (50 and 80%), while the state of clay (medium and stiff) corresponded to undrained shear strengths (50 and 70 kPa). All tests were carried out under load amplitude of 2.5 kN. It was found that the rate of increase in shear strength parameters for the soil under a circular machine foundation decreases remarkably when increasing the frequency for both types of soil under the footing. While little change in the shear strength parameters, or even no change was observed under the effect of other locations. Moreover, the amplitude strain decreased when increasing the frequency for both types of soil.

To ensure safe design of structures against settlement, it is necessary to determine the compressibility parameters of the underneath soil especially compression and rebound indices. In this paper, an approach to forecast the compressibility parameters of gypseous soils based on index parameters was developed using Artificial Neural Networks technique. Two equations were developed to estimate compression and rebound indices using back propagation algorithm to train multi-layer perceptron, in which good agreements were achieved. The input parameters used were: the depth, gypsum content, liquid limit, plastic limit, plasticity index, passing sieve No.200, dry unit weight, water content and initial void ratio. Two output parameters were determined including compression index and rebound index. A parametric study was also conducted to investigate the generalization and robustness of both models. The findings indicate that both models were reliable within the range of utilized data. It was found that gypsum content has the highest effect on the compressibility index followed by water content, plasticity index, dry unit weight and plastic limit, while other parameters have lower effect. The gypsum content has the highest effect again on the rebound index followed by passing sieve No.200, initial void ratio, plastic limit and plasticity index, while other parameters have lower effect.

The aim of current study is to analyse the effectiveness of e-learning for the students at university level. Data have been collected through questionnaire and it was given to 700 students. The questionnaire was returned by 667 students and 94.9% of them are using different e-learning tools, techniques or platforms. Eight variables have been used to measure the effectiveness of e-learning. Cronbach’s alpha test is used to measure the reliability and internal consistency of the associated factors. The exploratory factor analysis is used to extract the variables and to measure the factors loading in the study. One sample t-test has been performed to test the hypotheses. The outcome of the study supports that e-learning is faster, time and cost friendly, appropriate to work independently, add value to the learning of the students, usable for the purpose of active learning, faster, quick response, applicable outside the class room and quality of e-learning is satisfactory which indicates e-learning is effective.

The world civilization is growing very fast and for this reason the utilization of internal combustion engines is increasing day by day. Environmental pollution concern and energy crisis all over the world recently forced the attention to control engines exhaust emissions and energy savings. But this internal combustion engine increases both regulated and unregulated emissions. This study shows the effect of hot EGR (Exhaust Gas Recirculation) and cold on diesel combustion and exhaust emission with neat diesel fuel in a diesel engine. EGR is a well-known process to reduce NOx. For the EGR system more NOx emission is reduced and for the use of EGR. Comparatively better overall engine emission is found with the EGR system.

This paper addresses the modelling of Ambartsumian equation using the conformable derivative as an application of the theory of surface brightness in astronomy. The homotopy perturbationmethod is applied to solve this model, where the approximate solution is given in terms of the conformable derivative order and the exponential functions. The present solution reduces to the corresponding one in the relevant literature as a special case. Moreover, a rapid rate of convergence has been achieved for the obtained approximate solutions. Furthermore, the accuracy of the obtained numerical results is validated via calculating the residual against the impeded parameters. It is shown graphically that the obtained residual approaches zero in various cases, which proves the efficiency of the current analysis.

In this study a computerised management system was developed to aid major contractors in improving cost control performance in construction projects. The system was developed by synthesising all construction cost-related functions into a comprehensive framework, taking into account both cost overrun factors and mitigating measures. These factors and measures were based on the findings of previous studies by the authors, in which 10 cost factors were specified as the most potentially controllable by contractors of an observed 59 influential factors identified in construction projects in Iraq. The system was then developed using Python programming language to incorporate the material, labour, and equipment costs of each construction activity. The system was then compared to in real life implementations in seven types of construction projects undertaken by the State Company for Project Execution of the Ministry of Transport, a major contracting company in Iraq, with the results showing that the system can be successfully utilised by major contractors for cost control during construction.

Horan Dam H4 is an earth dam located 18 km northeast Rutba town in Anbar province in Iraq. The main objective for dam construction is to save rainfall for agriculture purposes and some household uses. In this study, a mathematical model is developed to analyze water seepage through the dam under steady state. The upstream and downstream slopes stability of the dam are also evaluated by using four methods which are: Bishop, Janbu, Morgenstern-Price, and Ordinary method. In addition, a two-dimensional finite element model was developed using GeoStudio program. The results of seepage analysis clearly show that Horan Dam H4 is safe against failure. Furthermore, the obtained factor of safety of upstream and downstream slopes stability proves that the dam body is stable based on Janbu’s method of minimum value. Moreover, it was found that the soil shear strength parameters highly influence the dam stability in steady state condition.

Objectives: To assess the efficacy of adjunctive tamsulosin therapy in improving the success rate of laser-assisted semi-rigid ureteroscopy (URS) for removing proximal ureteral stones. Patients and Methods: This prospective study included 165 patients with proximal ureteral stones ≥10 mm. The patients were randomly assigned to a tamsulosin group (Group I, n = 81) receiving tamsulosin 0.4 mg daily for 1 week pre-URS and a control group (Group II, n = 84) without tamsulosin therapy. Treatment consisted of URS using a semi-rigid ureteroscope (7.5 Fr), followed by intracorporeal holmium: YAG laser lithotripsy. The patients were followed up regularly for 8 weeks after URS. Results: The operative time was 43.4 and 49.6 min in Groups I and II, respectively (p < 0.001). Scope to stone access rate was 93.8 and 82.1% in patients of Groups I and II, respectively (p = 0.022). The stone-free rate was significantly higher in Group I compared to Group II (74/81; 91.4% vs. 67/84; 79.8%; p = 0.035). The complication rate was significantly lower in Group I compared to Group II (17.3 vs. 38.1%, p = 0.003). Only minor complications were encountered and were managed conservatively. Conclusions: Tamsulosin therapy prior to semi-rigid URS improved ureteroscopic access to proximal ureteral stones, thus leading to an increased success rate and low morbidity.

In this paper, the influence of the following parameters on different modes of vibration response of model footings on sand is studied: (vertical, rocking and pitching load amplitude and frequency). To achieve the objective of this study, the model footing was selected to be rectangular footing with an aspect ratio (L/B= 1.33) i.e (L= length and B= width). A physical model was manufactured to simulate a steady-state harmonic dynamic load applied at different operating frequencies with the same load amplitude (0.5 ton). A total of (9) cases was performed taking into account different parameters. The loading frequency ranged from (0.5) to (2) Hz and the footing was rectangular with an aspect ratio (L/B = 1.33). The soil type used was dry sand having a relative density of (50%). The behavior of the soil underneath the footing was examined by measuring the strain using a shaft encoder and the amplitude of displacement using a vibration meter. It was found that the change in vibration mode made little effect of the final strain values under the same frequency and the amplitude of displacement in (Z) direction, while the amplitude of displacement in (Y) is higher, occuring under rocking vibration and higher value amplitude of displacement in (X) direction under pitching vibration under the same frequency.

The effect of the embedment depth of a circular footing resting on dry sand and subjected to dynamic load on the amplitude of soil displacement (Az) was investigated the present study. In order to simulate the conditions occurring in the field, a special testing apparatus with accessories was designed and manufactured to study the effect of dynamic load on soil. A total of 18 cases were examined to take into account the effects of different parameters, including different frequencies (0.5, 1, and 2 Hz); relative densities (medium sand, R.D=50% and dense sand, R.D=80%); and corresponding unit weights (17.52 kN and 18.33 kN). All tests were carried out under load amplitude of 0.5 tons. The behaviour of the soil underneath the footing was examined by measuring the amplitude of displacement AZ using a vibration meter placed at a set depth (B) under the footing. It was found that when the embedment depth is changed from zero (at surface) to 0.5 B and then to B the value of amplitude of the displacement Az is reduced. The percentage of reduction in Az was about 4 to 39 % at depth 0.5 B, and about 37-77 % at depth B.

This research was conducted to investigate the effect of using internal steel plates for shear reinforcement on flexural behavior of SCC beams instead of using traditional reinforcement bars (stirrups) and to study the effect of their spacing and thickness on strength. The experimental work included destructive tests on six SCC beams under two-point load. The results showed that the yield loads in all of the beams with steel plates were lower than the reference beam by (5.21%) on average, the deflection at yield load was higher by (13.72%) on average and the ultimate loads were lower by (6.77%) on average except in one beam where it was higher by (0.37%). It was also found that the ultimate deflection in beams with internal shear steel plates was lower by (10.01%) on average except in the aforementioned beam where it was higher by (2.31%). Ductility in all beams with steel plates was lower by (20.08%) on average and the strain before a load of (200kN) was higher in the longitudinal reinforcement and lower in shear steel plates and vice versa after a load of (200kN). Theoretical analysis was also carried out for all beams using the finite element program ANSYS (version 15) where theoretical results of load versus mid-span deflection relations, longitudinal reinforcement strain, shear reinforcement strain, variations of neutral axis depths and cracks patterns showed good agreement with experimental ones. Finally, some specific further studies were recommended.

Public school building projects in Karbala Province experiences payment problems due to improper cash-flow planning by both parties; contractors and clients. These payment problems lead to work stoppages and conflicts. This research aims at developing a suitable model to forecast the expected contractors’ cash-in-flow in public school building projects in Karbala based on historical data. Complete sets of interim payments of (33) out of (38) school building projects finished in the years (2007-2012) in Karbala were interpolated using seven different regression methods namely; Polynomial, Gompertz, Morgan-Morgan-Finney, Logistic, Exponential, Gaussian and Linear in order to identify the best-suited model. It is found that the third degree polynomial model is more suitable for cash-in-flow forecasting of the case under study with coefficient of correlation of (97.89%) and standard error of (0.0441). Data of the remaining (5) projects were used to test the validity of the best-fitted model using Mean Absolute Percentage Error, Root Mean Square Error and Average Accuracy Percentage. The model is expected to be of high advantage in predicting contractors’ cash-in-flow in public school building projects in Karbala, and consequently clients’ cash-out-flow as well.

In nanofluid mechanics, it has been proven recently that the no slip condition at the boundary is no longer valid which is the reason that we consider the effect of such slip condition on the flow and heat transfer of two types of nanofluids. The present paper considers the effect of the velocity slip condition on the flow and heat transfer of the Cu-water and the TiO2-water nanofluids over stretching/shrinking sheets in the presence of a magnetic field. The exact expression for the fluid velocity is obtained in terms of the exponential function, while an effective analytical procedure is suggested and successfully applied to obtain the exact temperature in terms of the generalized incomplete gamma function. It is found in this paper that the Cu-water nanofluid is slower than the TiO2-water nanofluid for both cases of the stretching/shrinking sheets. However, the temperature of the Cu-water nanofluid is always higher than the temperature of the TiO2-water nanofluid. In the case of shrinking sheet the dual solutions have been obtained at particular values of the physical parameters. In addition, the effect of various physical parameters on such dual solutions is discussed through the graphs.

The influence of second-order velocity slip on the MHD flow of nanofluid in a porous medium under the effects of homogeneous-heterogeneous reactions has been analyzed. The governing flow equation is exactly solved and compared with those in the literature for the skin friction coefficient in the absence of the second slip, where great differences have been observed. In addition, the effects of the permanent parameters on the skin friction coefficient, the velocity, and the concentration have been discussed in the presence of the second slip. As an important result, the behavior of the skin friction coefficient at various values of the porosity and volume fraction is changed from increasing (in the absence of the second slip) to decreasing (in the presence of the second slip), which confirms the importance of the second slip in modeling the boundary layer flow of nanofluids. In addition, five kinds of nanofluids have been investigated for the velocity profiles and it is found that the Ag-water nanofluid is the lowest. For only the heterogeneous reaction, the concentration equation has been exactly solved, while the numerical solution is applied in the general case. Accordingly, a reduction in the concentration occurs with the strengthening of the heterogenous reaction and also with the increase in the Schmidt parameter. Moreover, the Ag-water nanofluid is of lower concentration than the Cu-water nanofluid. This is also true for the general case, when both of the homogenous and heterogenous reactions take place.

Objective: To evaluate oncological outcomes of Kidney Sparing Surgery (KSS) for upper urinary tract transitional cell carcinoma (UUT-TCC). Patients and Methods: We performed a retrospective review of patients who underwent segmental ureterectomy or endoscopic treatment (percutaneous nephroscopy or retrograde ureteroscopy) for UUT-TCC between 1991 and 2006 at our institution. We evaluated recurrence-free and overall survival rates following KSS. There were 40 renal units in 38 patients. Three patients had bilateral synchronous disease. Mean patient age (±SD) was 69.8±12.3 years. Eighteen (47%) patients had a prior history of bladder TCC. Sixteen (40%) segmental ureterectomies and 24 (60%) endoscopic treatments were performed. Six (16%) patients received adjuvant BCG. Grade distribution was 24 (60%) low-grade, 12 (30%) high-grade and 4 (10%) Gx. The mean follow-up was 47 months. Results: Recurrence rate was 32.5%. The three and five-year recurrence-free survivals were 59.5% and 42.4%. Tumor location was predictive for recurrence (p

Although, many exact solutions were obtained for the cubic Schrödinger equation by many researchers, we obtained in this research not only more exact solutions but also new types of exact solutions in terms of Jacobi-elliptic functions and Weierstrass-elliptic function.

The aim of this research is to create a fuzzy logic model that can aid in assessing payment problems encountered in construction projects in Iraq. The model was created based on the findings of a previous study of the authors in which (67) causes of payment problems in construction projects in Iraq were identified. The causes were ranked by (72) professionals from (38) Iraqi firms based on the frequency and severity of causes. All causes were employed in the model after categorizing them in four groups: owner-related, contractor-related, consultant-related and external causes. The model was constructed using MATLAB Program Software Version 2. Finally the model was tested against (10) real life projects and found to be appropriate to aid owners and contractors in the Iraqi Construction Industry to early assess payment problems in order to take preventive actions.

The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while stakeholders of government funded school buildings projects are experiencing the ill effects of extreme delays caused by many reasons. Those stakeholders are particularly worried to know ahead of time (at contract assignment) the expected completion time of any new school building project. As indicated by a previous research conducted by the authors, taking into account the opinions of Iraqi experts involved with government funded school building projects, nine major causes of delay in school building projects were affirmed through a questionnaire survey specifically are; the contractor's financial status, delay in interim payments, change orders, the contractor rank, work stoppages, the contract value, experience of the supervising engineers, the contract duration and delay penalty. In this research, two prediction models (A and B) were produced to help the concerned decision makers to foresee the expected completion time of typically designed school building projects having (12) and (18) classes separately. The ANN multi-layer feed forward with back-propagation algorithm was utilized to build up the mathematical equations. The created prediction equations demonstrated a high degree of average accuracy of (96.43%) and (96.79%) for schools having (12) and (18) classes, with (R2) for both ANN models of (79.60%) and (85.30%) respectively. It was found that the most influential parameters of both models were the ratio of the sum of work stoppages to the contract duration, the ratio of contractor's financial status to the contract value, the ratio of delay penalty to the total value of contract and the ratio of mean interim payments duration to the contract duration.