University of Thi-Qar Journal for Engineering Sciences

The driving cycle is a critical factor in measuring fuel consumption and exhaust emissions. Because vehicle exhaust emissions from road transport are the primary contributors to emissions around the world, so the study of the driving cycle is a vital way to solve the difficulties of environmental pollution. This paper presents a new real-world driving cycle for Nasiriyah, Iraq. A simple electronic device is designed to build the driving cycle after collecting speed data; the system consists of Arduino and a Global Positioning System (GPS) sensor connected to a computer. The technique involves producing micro-trips extracted from real-world driving. Using the K-means clustering method, the Statistical Package for the Social Sciences (SPSS) was used to design this driving cycle. The built driving cycle has a 1568 s speed time series, with an average velocity of 26.7 km/h and a distance of 11.64 km, according to the results. The effectiveness and accuracy of the proposed method were verified when the drive cycle was compared to other types of driving cycles. These results findings strongly support the use of hybrid electric vehicles (HEVs) in Nasiriyah city.

In this paper, heat transfer enhancements using unique, various sets of teardrop-shapes inserts in a heating tube are numerically examined. The teardrop is a hemispheric placed on a conic part. The three-dimensional continuity, momentum and energy equations are repeatedly solved using ANSYS 17.1 software at turbulent flow regime with Reynolds number varies from 10000 to 30000. Nine cases are investigated excluding the plain tube case by changing the ratios of hemisphere diameter and conic part length to the tube diameter, dr and lr respectively. The tube was of diameter and length of 30 mm and 1000 mm respectively. The tested ratios were dr = 1/3, 1/2 and 2/3 while the ratio lr =5/3, 7.5/3 and 10/3. The results show that Nusselt number increases with increasing both dr and lr and vice versa because the greater dr interrupts the flow and therefore boosts swirling power in the tube. Similarly, the friction factor behaves as a consequence of the large blockage presence. However, the thermal performance factor TPF is less at the greatest dr and lr ratios, and the optimal one is obtained when the equipped teardrops were of dr=2/3 and lr=5/3 recording TPF=1.32 which is the most thermally efficient case among the rest. Over the empty tube, the percentage increase in TPF is 32% and 11% at Re=10000 and Re=30000 respectively. While the percentages in comparison with the smallest dr and lr are 11.8% at Re=10000 and 4.7% at Re=30000.

The pressure drop оn а boiling flow fоr а micro-channels оf hеаt sink wаs reportеd with the R123 аs а working liquid fоr this hеаt sink. The liquid hаs аn inlet temperature (20 °C), (8) mass flux speeds fоr same inlet temperature (160 -300 kg/m2.sеc) and the hеаt applied tо vary from (10 tо 15 kW/ m2). So, а square copper оf micro channels оf hеаt sink hаs (25) channels each channel hаs (0.1 mm) channel height and (0.5 mm) width channel. So, the prediction оf single-phase and fоr two-phase оf hеаt transfer cоefficient and predictive оf wall temperature wаs addressеd in this paper. This paper also guessеd а hеаt flow оf micro-channels. А piece оf copper plate hаs dimensions (25 mm) width bу (25 mm) length and (5 mm) depth wаs subsequently developеd fоr а square оf copper plate. So the square copper оn micro-channels оf hеаt sink hаd heаtеd bу аn electric heаtе.So It hаs bееn reportеd and documentеd that the properties оf geometrical structure and test piece metal contribute tо the prediction оf single-phase and fоr two-phase hеаt transfer cоefficient functions. Аn iteration process bу excel software wаs employеd tо gеt properties оf flow hеаt such аs; а single-phase and two-phase оn pressure drop оf hеаt transfer wаs clearly bееn laminar also a fullу developed оn this flow, а prediction оn wall оf temperature, а prediction оn fluid оf temperature аt prediction tests. А potential mechanism оf hеаt transfer wаs reportеd fоr micro-channels оf hеаt sink. Sо results оn the main оf this paper tо acquire аn inlet and аn outlet а prediction оf hеаt flow, such аs а temperature оf liquid; а temperature оf wall; а cоefficient оf hеаt transfer. In addition tо mention fоr some оf numerical results such аs the liquid оf Reynolds numbеr hаd (54-101) also two-phase оf Reynolds numbеr hаd (412-846); а single-phase оf pressure drop wаs (50-211) Pascal. Аt end, I would like tо mention that nо experimental dаtа cоme оf prediction sеt-uр sо that R 123 dаtа come оn prediction analysis wаs only employеd bу equations оf hеаt transfer аt guess sеt-uр Very similar tо real lаb tests under tо same conditions.

This investigation hаs bееn studied tо а complex geometry оf flat channels. А piece оf copper plate by dimensions (25 mm) width by (25 mm) length and (5 mm) depth wаs, therefore, developеd fоr copper plate, it wаs а square shape. The hеаt wаs applied оn range (50-600) watts (3) mass оf flow rate hаd employеd. The ranges оf hеаt hаd applied fоr each flow оf mass wаs employеd. The square copper оf flat geometry with а channel height (3 mm) and а channel length (25 mm) is heatеd viа аn electric heatеr. It hаs bееn researchеd and reportеd that the characteristics оf а geometrical structure and оn metal contribute tо test piece tо guess оf cоefficient оf single-phase оn hеаt transfer and tо guess оf cоefficient оf two-phase оn hеаt transfer.Аn iteration process viа excel software wаs utilized tо gеt properties оf flow hеаt such аs; а coefficient single-phase and а cоefficient two-phase оf hеаt transfer wаs clearly bееn laminar also a fullу developed оn this flow, а guess оn wall оf temperature, а prediction оn fluid оf temperature аt guess tests. А possibility mechanism оf hеаt transfer wаs reportеd fоr flat-channel оf complex geometry. Sо results оn the main оf this article tо acquire аn inlet and аn outlet а guess оf hеаt flow, а fluid temperature, аs well аs gеt coefficient оf single-phase and а cоefficient оf two-phase оn hеаt transfer in addition tо mention а some оf numerical results such аs the liquid оf temperature fоr inlet location hаd bееn between (20.84 -32.63) Celsius also liquid оf temperature fоr outlet location hаd bееn between (21.40-45.26) Celsius; а temperature оf wall hаd bееn between (40.70-48.60) Celsius.. Ultimately, sо I have nо experimental dаtа hаd obtainеd оf empirical sеt-uр sо that R113 dаtа hаd obtainеd оn guess analysis wаs only employеd bу equations оf hеаt transfer аt guess sеt-uр very similar tо real lаb tests under tо steady-state conditions.

The research aim is to assess the seismic performance of an asymmetrical RC building using NTHA. The building was built in the southern Iraqi city of Basra. Southern Iraq is categorized as a low seismic region in ISC1997, however, the current ISC2017 has been updated and contains specific seismic requirements to be applied for the construction of new buildings, prompting the need to assess the state of existing buildings concerning these new requirements. The case study is irregular in plan floors and vertically, causing it more vulnerable to severe deformations and damage than buildings with regular plan floors. The analysis is based on the ISC2017 in the design of the RSC and the modern US standard code ASCE7-16 in the selection of GMs.

The smart stretcher is a device used to transport individuals who need medical attention, the stretchers are typically utilized by emergency medical services (EMS). The suggested prototype of smart stretcher model consist of A two-parts: the upper part (portable stretcher consist of central bed, middle part and handle part), and the lower part consist of the passive and active suspension systems. The portable stretcher is suggested to reduce the disturbance to patient, where the control system is consist of the Arduino Uno, two stepper motors (for controlling the pitch and the roll motions), the MPU6050 for sensing the roll and pitch angles of handling part and two of the SC60C sensors are placed in the central bed for measure it’s the roll and the pitch angles. In this study, the Simulink/MATLAB was used to investigated and controlling by using the PID controller with the active suspension to reduce the vibrations which transfer to upper part. Form the suggested model of smart stretcher can conclude the active suspension show the effective suspension and can be use in transporting of patients.

For the safety of buildings and institutions that are established on weak or collapsing soils(sand and clay) characterized by high permeability and continuous subsidence, it has become necessary to improve and strengthen the soil. In this theoretical research, the focus was on the method of soil injection with the jet grout system through modeling models of clay and sandy soils with different geometrical properties dimensions (10 m x10m) based on the PLAXIS 3D 2020 program, load displacement curve was calculated and the soil bearing capacity was calculated on the shallow Foundation with dimensions (1m x1m) by injecting a single jet grout column with (D = 0.5 m) and ( L =10 m).

The result of the improvement in bearing capacity was noticeable after injecting the jet grout column for clay soil types (soft, medium, and stiff) as well as for sandy soil types (loose, medium, and dense).

The structures are flexible and their structural stability should be provided under all conditions. The bearings are the key member that offers freedom of movement between the superstructure and the foundation while accommodating vertical loads and rotation. Based on the finite element software ANSYS19.2, the FE model for a reinforcement elastomeric bearing is developed. The design parameters of the bearing, including elastomer thickness, shape factor, steel thickness, b/h ratio and number of steel shims are examined, and numerical results are verified by results of the previous researches. In this study, for the specific elastomeric bearing, the effect of shape factor and the number and thickness of reinforcing plates on its compression and shear stiffness is studied by using ANSYS Mechanical APDL. Results show that the FE model is capable of predicting the vertical stiffness and size of bulging (horizontal movement).

Traffic calming" refers to the practice of reducing the amount of accidents on the road via the use of physical design measures and other methods. The goal is to decrease excessive speeding and other potentially dangerous driving practices in residential areas. The construction of speed bumps is one of the most efficient methods of limiting the speed of moving vehicles while simultaneously improving public safety. A field survey of the road network in Nasiriyah and its surrounding facilities was carried out, in addition to a comprehensive data collection that was used in the GIS program (ArcMap 10.7) to produce maps showing the different types of bumps and the mechanism by which they are distributed in Nasiriyah, taking into consideration the facilities and surrounding structures, as well as the facilities themselves. Ultimately, it was determined that the short bump is a centralized and most appropriate bump for the Nasiriyah road network due to the ease with which it can be obtained. Furthermore, it is regarded to be less costly than other types of bumps. The nature of the study areas roadways and service center make the usage of short bumps a more appropriate solution. Utilizing bumps to calm traffic in the city of Nasiriyah enhances the reality of the streets as well as adds civilized touches to the roadways and helps to clear the city of slums by using the proper kinds in the suitable places at the appropriate time.

The behavior of corrosion of AZ31 Mg alloy was studied in (SBF) “Simulated Body Fluid” by electrochemical analysis technique to realize the role of coating with (Ti) by DC sputtering with the absence and presence of oxygen. The coating by (Ti) with the absence of oxygen enhanced the stability of the corrosion product as MgO through decreasing the corrosion current density. While the presence of oxygen during coating accelerated the corrosion rate due to increasing the cathodic polarization through the reduction of oxygen and then increasing the dissolution of Mg from the substrate. The coating by (Ti) gave protection efficiency reach (33.742%). While the presence of oxygen during DC sputtering promotes the cathodic area on grains as ( ) leading to localizing the corrosion around the phases at the grain boundaries.

Because of its high corrosion resistance and ability to preserve mechanical qualities at high temperatures, Stainless steels are used in a variety of applications, including automotive, aerospace, and marine. In metal turning, cutting speed, feed rate, and depth of cut are all essential machining parameters . The settings of these parameters determine the quality of the final turning results. The goal of this research is to see how changing these parameters affects the output factor (Surface Roughness). In addition, the behavior of stainless steel 440 C in dry turning conditions is being investigated for purpose to improve cutting conditions. In response surface methodology (RSM), the box-behnken design (BBD) technique is used, the surface roughness was modeled as a result to the parameters of cutting. The 17 trial runs were built using Design Expert (v12) to develop and test the empirical surface roughness mathematical model. The results indicated that the roughness is strongly affected by the feed rate, followed by cutting speed and depth of cut.

This review discusses the properties of different materials that are used to strengthen the reinforcement concrete members by using developed and classical materials. Frequently, steel-reinforced material and fiber reinforced polymer (FRP) material are used to increase the strength of concrete members. Also, the Near-surface mounting technique for increasing the strength of concrete members is discussed. At the serviceability, the Near-surface mounting techniques have given an acceptable result for increment in applied load and increased the stiffness of concrete members after cracking.

Solar energy is the sun-emitting light and heat that man has used a wide variety of developing technologies since ancient times techniques for solar energy include the use of solar thermal energy, whether for direct thermal heating or as part of the process of mechanical conversion for movement or electric energy, or the use of photovoltaic panels for electricity through photovoltaic panels.

Alongside secondary energy sources like wind energy, wave energy, hydroelectric power and biomass, most of the renewables accessible on the Earth's surface are attributable to solar radiation. It should be pointed out that in our lives just a little of the solar energy accessible has been utilized Solar energy produced by heat engines or photovoltaic converters produces electricity .electricity only human genius regulates its applications after solar energy is transformed into electric power heating and cooling systems in architectural designs depending on the exploitation of solar energy are among the applications created utilizing solar energy. Drinking water, sunshine, water heating, solar cooking and heating for industry uses, during distillation and disinfection .In general, solar technologies are described as passive solar energy systems or passive solar energy systems depending on how sunlight is used, processed and dispersed. The use of photovoltaic panels and a solar thermal collector with mechanical and electrical equipment for converting sunlight into other usable energy sources are technologies that rely auf the use of positive solar energy .this is done by using passive solar energy to direct a structure to the sun, use materials with the corresponding thermal mass or light disseminating characteristics and create spaces , which circulate the air naturally. In this research, the total solar energy calculations for the city of "Nasiriya" are found from the total direct and dispersed energy as well as reflected through its own laws, and the geographical location and the angles of inclination of solar radiation and the angles of inclination of the receiving solar complex to the sun for three times during a day in every month over the course of The year is in addition to the ground reflectivity factor, and some other factors such as clouds, humidity, dust and smoke have been excluded from the calculations.

This paper investigates a comparison of wear behavior under laser surface hardening for two different kinds of aluminum alloys. Experimental investigations of wear processing were carried out under different load conditions 5, 10,15,20,25 N and with constant sliding speed 2.199 m/s for 15 min. Also changing sliding velocities 1.319, 2.199, 3.078, 3.958 m/s with constant load 20 N for 15 min. Wear machine operate with constant disc rotating at 750 r.p.m. Trails of laser hardening were performed by using pulse Nd:YAG laser with three level energies 500 , 750 , 1000 mJ. Different wear tests were made such as, measurement of depth of hardening, micro-hardness and microstructure examination. This work is shown that the highest amount of laser energy is affected on increasing the micro hardness of 2024 alloy, while it has little or no effect of laser treatment for 7075 alloy. Also wear rates were significantly decreased for 2024 alloy more than 7075 alloy. Photomicrographs show that refining of grains after laser treatment for 2024 alloy more than 7075 alloy.

Although ' Identity ' in its total and popular sense, has the great ancientness and equality with the human being civilization history, the record of this controversy is not so much precedent. Ease and abstainer of the sense of identity in the process of recognition and perception, bring us amulti-dimensional and complicated phenomenon.

Since the city is a window for presentation of community thoughts to the outer world and is the bedrock for creation of civic life, relation of identity and urban landscape become an effective category on correlated sciences with this zone and effort to find out the essence of urban landscape for evaluation of immense intervention politics on current cities is obligatory.

This article aims to describe identity and urban definitions by applying the recent theory of ' Urban Landscape Identity ' and quantize identity as a qualitative object as well as analyzing different dimensions of this
concept and finally contribute to its concise literature.

Because of the following reasons, the aim of this paper is not to present minute strategies for continuing the identity of urban landscape:

First, the urban studies are so vast that it is not possible to present a certain approach for that.

Second, prerequisite of detailed approach is presentation of voluminous report, which will be far from the aim of this paper.

Third, It's the first time that this subject is introduced in an academic paper and it's seemed that basic and extended analyze is more beneficial than minute technique programming.

The flow of oil-water mixture in a pipeline can take place in a variety of patterns. It’s appear during the transportation of oil and in wellbore. The fraction of water in the output stream will increase as the producing life of a well increases. Being able to estimate the pressure loss in such systems is critical for properly designing the conveying system. In this study the ANSYS fluent 2021 R2, the VOF method the RNG, k- model were used to simulate three dimensional turbulent flow of the oil-water flow in elbow pipe of 55.57mm diameter and straight pipes at its two side of 800mm length with three water volume fractions 25%, 50%, 75%. The flow pattern and the distribution of the velocity and the influence of the elbow angle on them were studied. Also prediction of the pressure drop and the effect of water volume fraction and the influence of elbow angles on it. The result show that the pressure drop increase by increasing the water volume fraction, and the largest pressure drop happened at 90o elbow angle while the lowest at 45o.

Ships are considered one of the most important means of transportation in the world, especially at the present time, These ships are exposed to harsh climatic conditions, and The loss of people and cargo, as well as the loss of ships, are all repercussions of these situations. In this research, the fin with the flap was studied practically, and the aim of it is to study several angles of the flap to achieve the best balance for ships at several speeds. Where the fin was made according to the international standard NACA 0015, with a length of 30 (cm) and a width of 13 (cm) of aluminum alloy with a flap length of 4( cm) and a width of 14 (cm) of aluminum alloy as well. Where it was installed in a wind tunnel device with the fluid pressure applied to it and changing the angle of the flap to 9 angles, also using 5 speeds for each angle and calculating the vibration of the flap using the Vibration Meter device at each angle and for each speed It was found that the least vibration occurred at the angle of 15ͦ , so it is preferable to adopt this angle when designing the wing in order to balance the ship.

The performance of a centrifugal pump employing a single-step centrifugal pump under a gas-liquid mix and with a single suction pump is displayed. volume fracture ratios, IGVF % (1,5,10,15) 2compared with the flow rate Q/Qdes,w (8-1,2), the experimental and numerical simulations have been compared. The findings are presented by coefficients without dimensions from the similarity law. The computational results have shown that the nominal rotational velocity of numerous flow parameters has achieved good agreement on the experimental data, with the degradation in the head being noticed step by step, i.e. the bigger the volume ratios, the more the head deterioration is. The coefficient of inflow declines

Geotechnical engineering work becomes challenging when the sub-grade is revealed to be silt or silty clay soil. Clay-rich soils inflate when the moisture level in the soil is allowed to rise. Because of their geologic nature, textural qualities, and climatic conditions, most soils in the south of Iraq have a well-known diversity of formations among the world's soils. Because the soil particles are surrounded by molecules of chlorides, sulfates, or other species of salts, which act as link agents to fill in the gaps in the dry condition, most soils in the Marshes area of Thi-Qar Governorate can be classed as saline soils. The sort of salt in such soil determines how it is disposed of. Chloride salts, for example, are more common and more readily dissolve in water The goal of this research is to improve the geotechnical qualities of soil by using Portland cement and different chloride salt compounds. Salt concentrations of 2%, 4%, 8%, and 10% were applied to the soil to see how they affected compaction characteristics and consistency limits. According to the findings of the study, increasing the amount of each chloride component raised the maximum dry density while decreasing the optimum moisture level. As salt content grows, the liquid limit, plastic limit, and plasticity index all drop.

Carbon steel pipelines used in oil and gas transportation suffer from top of line corrosion (TLC). This persistent issue endangers the safety of the pipeline network. Corrosion at 10-2 o’clock position could occur as a result of the condensation process of water vapor containing CO2 and H2S acidic gases. Due to the difficulty of reaching inhibitors to the top of the pipeline, this type of corrosion represents a big challenge to the oil and gas industry. The injection of corrosion inhibitors is a typical method for corrosion mitigation. The conventional corrosion inhibitors employ in the petroleum industry are non-volatile liquids, and they hardly reach to the top of the pipeline where the condensed water which contains corrosive species, for instance, CO2 and H2S is accumulated. Rendering this mitigation technique unable to prevent the TLC, therefore, TLC is a major challenge in the oil and gas industry. This study details the work carried out to develop an inhibitor performance and presents a novel volatile corrosion inhibitor that prevents the TLC in marginally sour environments. An innovative glass cell setup was designed and applied in the study, to simulate the TLC process in conditions similar to field experience and to improve the experimental data quality. Weight loss measurement technique was conducted to find the TLC rates in the presence and the absence of the volatile corrosion inhibitor. The gas-phase concentrations of H2S started from 0.015 of up to 0.15 mbar. . Upon injection of the inhibitor, the results showed that the developed inhibitor could effectively mitigate and reduce the corrosion rate at the top of the pipe which suggests its potential application in the oil and gas industry.

The current study was devoted to investigate experimentally and statistically the effects of different parameters on hexamine production in a bench-scale setup operating in a batch mode. The operating variables were varied in the range of (formaldehyde/ammonia) ratio =2 to 10; temperature = 20 to 80 oC; process time = 0 to 100 min). Experimental results revealed that a positive impact of (formaldehyde/ammonia) ratio on the production process was observed across the studied range, while temperature and time showed optimum values of 60 oC and 60 min, respectively for the optimum % yield of hexamine is 98%. Statistical analysis of the process showed that the Model F-value of 17.63 reveals the model's significance. While there is only a 0.01% chance that a "Model F-value" could come because of noise. Values of "Prob > F" less than 0.0500 point model codes are significant.

This paper presents a mathematical model for detecting a single-phase to ground fault by using the frequency characteristics. The variety of types of single-phase-to-ground faults on overhead power lines significantly complicates the development of one universal method for its recognition and determination of the alleged place of damage. An additional aggravating factor is the complex configuration of district electrical networks, where up to several dozen consumers can be on one feeder, and the total length of its overhead line reaches several tens of kilometers. The most dangerous demonstration of single-phase to-ground fault is the resulting overvoltage’s in the network. The intermittent arc at the site of the single-phase-to-ground faults serves as a source of higher harmonics, which, in turn, due to "resonant" phenomena, can reach unacceptable values. It follows that for the correct reproduction on mathematical models of emerging phenomena, it is necessary to use the mathematical theory of long lines. Higher harmonics caused by single-phase-to-ground faults can serve not only as an indicator of the occurrence of damage, which is already being implemented in existing microprocessor relay protection terminals, but also provide information on the approximate location of the site with single-phase-to-ground fault. The mathematical model is initiated from a simplified equation for long distance transmission. To asses the accuracy of the calculation performed for the power transmission in equation its model was made in the Simulink Package and the overhead line was introduced into the model as an object with distributed parameters.

Increasing the level of short-circuit currents on the buses of the power center leads to the upsetting the resonant peak of the frequency response signal relative to the beginning of the line, which makes it preferable to use frequency characteristics relative to the end of the transmission. In this case, combinations of network parameters and the magnitude of the contact resistance are possible, when the "resonant" amplification of higher harmonics is not evident

In all Countries, road pavements are recognized as one of the most critical structural components. Attention must be paid to the management of maintenance work and its timely execution in order to keep the pavement in good conditions and acceptable service level. Pavement distress check is very beneficial to the capabilities of Pavement Management Systems (PMS). The objective of this research is to connect the PAVER software database to A GIS software in order to perform spatial analysis of pavement condition and develop location-related heat distress maps based on Pavement Condition Index (PCI) values. A visual survey of the research area was conducted to evaluate the type, level, and amount of defect. The PAVER 6.5.7 software was used to calculate the PCI values for each sample unit based on the data collected from the visual survey. The data obtained by the PAVER program was integrated with ArcGIS software 10.4 in order to create heat maps utilizing spatial analysis tools .



The heatmap shows the type maintenance for the study region based on PCI values, with each category of PCI values represented by different colors. Each color on this map represents a different sort of maintenance, with red indicating that the pavement requires rebuilding, yellow indicating rehabilitation, and green indicating preventative maintenance. PCI values over 85 indicate that the pavement is in excellent condition and does not need to be maintained. Using the heat map . In general, the selected roads in Nasiriya city is quite and in acceptable conditions, although there is some patching and weathering practically everywhere, and the road needs to be covered with overlay asphalt layer.

This paper offering a wide-ranging study to investigate the punching shear behavior of reinforced concrete flat slab. The study involved of thirteen specimens tested under static load and divided into two groups; the study included one solid slab which considered the control slab. While the remaining slabs were parametric strengthened slabs with openings. The used variables were the opening size in addition to the strengthening of these openings by steel reinforcement. Six opening sizes (100x100, 150x150, 200x200, 250x250, 300x300, and 350x350) mm were constructed and tested under punching shear load. The results showed that the slabs behave linearly until it reaches about average value 23.5% of their ultimate strength for solid slab and by (17.2%) for the slabs with opening. The openings presence affected the load carrying capacity which decreased the cracking load by (45.8%) and ultimate load by (32.2%) when compared with the solid slab. Regarding the opening size, increase of the size led to decrease in the cracking and ultimate load of the flat slab which the opening with size of (350 x 350) mm caused maximum decrement which was by (60.75%) when compared with the solid slab. Reinforcing the opening with steel reinforcement could compensate the lost strength for small openings while the larger openings (greater than 150 x 150) compensated some strength due to the high condensation of shear stresses. The ductility of tested flat slabs was decreased with the existence of the opening and enhanced when the openings reinforced with steel reinforcement.

This paper offerings a wide-ranging study to investigate the punching shear behavior of reinforced concrete flat slab with openings. The study involved of eighteen specimens tested under static load and divided into two series; the first group included flat slabs with openings while the second series were slabs with openings with varied compressive strength. The used variables were the opening location and number in addition to the compressive strength of slabs (40,50, 60, and 70 MPa). The results showed that the slabs behaves linearly until it reaches about average value 23.5% of their ultimate strength for solid slab and by (23%) for the slabs with opening. The openings presence affected the load carrying capacity which decreased the average cracking load by (31%) and ultimate load by (28%) when compared with the solid slab. Regarding the opening location, placing the opening near the central column led to decrease in the cracking and ultimate load of the flat slab with maximum decrement in the ultimate load was by (60.2%) when compared with the solid slab. increase of the compressive strength enhanced punching shear strength of the slabs with opening. The ductility and energy absorption of flat slabs were decreased with the existence of the opening and enhanced when the compressive strength increased.

The purpose of this article is to investigate the influence of commercial pure (0.04 mm thick) AL-foil and commercial pure (0.1 mm) Cu-foil at the interface of lap-joint on the characteristics of welds galvanized AISil 005 steel after welding throughthe tensile-shear testing. It was discovered that raising the welding current increases the size of the fusion zone. Due to the low current of spot-welding, the welds failed in an interfacial manner. Increasing the welding current results in adequate weld size and encourages the failure mechanism of double pullout with enhanced mechanical characteristics. Nonetheless, a further increase in welding current resulted in metal ejection and a modification of the failure mechanism with diminished mechanical qualities.The size of the fusion zone was determined to be the most influential factor in determining the mechanical characteristics of AISil 005 spot welds. The use of an AL interlayer boosts the galvanized AISI 1005 steel's mechanical characteristics and weldability. Cu interlayer addition diminishes the mechanical properties and weldability of galvanized AISI 1005 steel because it causes steel solidification cracking.