Portland cement concrete is the most commonly used construction material in the world for decades. However, the searches in concrete technology are remaining growing to meet particular properties related to its strength, durability, and sustainability issue. Thus, several types of concrete have been developed to enhance concrete performance. Most of the modern concrete types have to contain supplementary cementitious materials (SCMs) as a partial replacement of cement. These materials are either by-products of waste such as fly ash, slag, rice husk ash, and silica fume or from a geological resource like natural pozzolans and metakaolin (MK). Ideally, the utilization of SCMs will enhance the concrete performance, minimize environmental pollution and mitigate the drawbacks of cement production attributed to the highly CO2 emission. In general, MK's ultra-fineness and high pozzolanic activity are exhibited a remarkable performance of concrete in terms of strength and durability. However, the filler effect, acceleration of cement hydration, and the pozzolanic reaction with calcium hydroxide (CH) are the main factors influencing the performance of metakaolin as a cementitious material. Therefore, numerous researches have been undertaken on inclusion MK in concrete and mortar and production of (free-cement concrete) geopolymer concrete. This paper reviews some of previous native researches on effect of using Iraqi metakaolin as a pozzolanic material in different types of concrete. The standpoint of this review will guide the researchers on the importance of utilization of local MK and highlight the missing researches toward completing a comprehensive understanding of incorporation Iraqi-metakaolin in concrete technology.
Most recognition system of human facial emotions are assessed solely on accuracy, even if other performance criteria are also thought to be important in the evaluation process such as sensitivity, precision, F-measure, and G-mean. Moreover, the most common problem that must be resolved in face emotion recognition systems is the feature extraction methods, which is comparable to traditional manual feature extraction methods. This traditional method is not able to extract features efficiently. In other words, there are redundant amount of features which are considered not significant, which affect the classification performance. In this work, a new system to recognize human facial emotions from images is proposed. The HOG (Histograms of Or
... Show MoreAn intrusion detection system (IDS) is key to having a comprehensive cybersecurity solution against any attack, and artificial intelligence techniques have been combined with all the features of the IoT to improve security. In response to this, in this research, an IDS technique driven by a modified random forest algorithm has been formulated to improve the system for IoT. To this end, the target is made as one-hot encoding, bootstrapping with less redundancy, adding a hybrid features selection method into the random forest algorithm, and modifying the ranking stage in the random forest algorithm. Furthermore, three datasets have been used in this research, IoTID20, UNSW-NB15, and IoT-23. The results are compared with the three datasets men
... Show MoreAbstract In this study, an investigation is conducted to realise the possibility of organic materials use in radio frequency (RF) electronics for RF-energy harvesting. Iraqi palm tree remnants mixed with nickel oxide nanoparticles hosted in polyethylene, INP substrates, is proposed for this study. Moreover, a metamaterial (MTM) antenna is printed on the created INP substrate of 0.8 mm thickness using silver nanoparticles conductive ink. The fabricated antenna performances are instigated numerically than validated experimentally in terms of S11 spectra and radiation patterns. It is found that the proposed antenna shows an ultra-wide band matching bandwidth to cover the frequencies from 2.4 to 10 GHz with bore-sight gain variation from 2.2 to
... Show MoreThe main aim of this paper is studied the punching shear and behavior of reinforced concrete slabs exposed to fires, the possibility of punching shear failure occurred as a result of the fires and their inability to withstand the loads. Simulation by finite element analysis is made to predict the type of failure, distribution temperature through the thickness of the slabs, deformation and punching strength. Nonlinear finite element transient thermal-structural analysis at fire conditions are analyzed by ANSYS package. The validity of the modeling is performed for the mechanical and thermal properties of materials from earlier works from literature to decrea
... Show MoreThis paper is devoted to investigate the effect of internal curing technique on the properties of self-compacting concrete (SCC). In this study, SCC is produced by using silica fume (SF) as partial replacement by weight of cement with percentage of (5%), sand is partially replaced by volume with saturated fine lightweight aggregate (LWA) which is thermostone chips as internal curing material in three percentages of (5%, 10% and 15%) for SCC, two external curing conditions water and air. The experimental work was divided into three parts: in the first part, the workability tests of fresh SCC were conducted. The second part included conducting compressive strength test and modulus of rupture test at ages of (7, 28 and 90). The third part i
... Show MoreThis paper introduces experimental results of eighteen simply supported reinforced concrete beams of cross sections ( ) and length 3000 mm to study the effect of lacing reinforcement on the performance of such beams under static and fatigue loads. Twelve reinforced concrete beams (two of them are casted with vertical shear reinforcement used as control beams) are tested under four points bending loading with displacement control technique and six laced reinforced concrete beams were exposed to high frequency (10 Hz) by fixing the fatigue load in each cycle. Three parameters are used in the designed beams, which are: lacing bar diameter (4mm, 6mm, and 8mm), lacing bar inclination angle to horizontal , and lacing steel rat
... Show MoreThe research aims to assess the local accounting procedures related in one of developments that have taken place, and largely on the structure of the Iraqi economic activity. But a partnership between the (public and private sector), or one of the types of joint arrangements, and through the use of the analytical method and extrapolate the reality of the accounting treatments in Company research sample. Research found to a number of conclusions that the unified accounting system applied in the economic units that deal with contracting joint arrangements formula suffers from obvious shortcomings, and reflected the common arrangements suffer from obvious shortcomings. and reflected on the quality of financial reporting, and the urgent need
... Show MoreEven though in recent decades a bulk of studies have been accomplished on the use of communicative language teaching (CLT) in English as a foreign language (EFL) environments, fairly a limited numbers of studies precisely dealt with investigating the attitudes of language teachers, students and supervisors concerning the principals of CLT in the context of Iraq. Henceforth, this study was designed to delve into the attitudes of teachers, learners and supervisors about the implementation. To this end, the study was accomplished using a mixed method design. The present study was carried out in two phases: designing and using a questionnaire plus interviewing the teachers, students and supervisors (51 language learners, 41 teachers and
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