Abstract
In this work, attempts are made to estimate the relationship between the ultrasonic wave parameters and the presence of the nitrided layer. Special samples were prepared, the surfaces of which were ground and then nitrided. The samples were evaluated by ultrasonic method before and after the nitriding. During the tests, three parameters of the ultrasonic wave were recorded i.e., time of wave propagation, dominant frequency of the spectrum and bandwidth. The measurements were repeated ten times. The obtained results indicate, in particular, a reduction in the wave propagation time in the samples after nitriding compared to the samples without the nitrided layer.
1 Introduction
In the process of manufacturing elements, nitrided layers are used on their surface. They are to improve the functional properties of the elements. There are several ways to create nitrided layers. Nitrided layers are used, for example, on the surface of crankshafts in engines or dies for extrusion of profiles [1].
After the layer has been produced, its quality is checked. One of the parameters in this evaluation is the thickness of the layer. The thickness is measured under a microscope on a metallographic specimen. This method is destructive. There are also non-destructive methods for assessing the thickness of nitrided layers. The eddy current method [2,3,4,5], Barkhausen noise [6] and ultrasonic method are used [7]. This work attempts to estimate the relationship between the ultrasonic wave parameters and the presence of the nitrided layer.
2 Nitriding of steel
Nitriding of steel is the process of saturating the surface layer with nitrogen. Nitriding is performed at an elevated temperature (usually 500–600°C) in an atmosphere containing free nitrogen atoms. Depending on the type of nitriding atmosphere, it can be distinguished into gas, ionic, powder and fluidized bed nitriding. Regardless of the type of nitriding, this process leads to the formation of a thin diffusion layer on the steel surface (Figure 1), which significantly increases the durability of the detail, and thus also of the entire technical objects.
![Figure 1
Nitrided layer on 40 HM steel [7].](/document/doi/10.1515/eng-2022-0401/asset/graphic/j_eng-2022-0401_fig_001.jpg)
Nitrided layer on 40 HM steel [7].
The nitrided layer is characterized by high hardness and resistance to abrasion, corrosion and fatigue. The structure, thickness and properties of the nitrided layer depend on the type of steel and the parameters of the nitriding process itself – temperature, nitrogen potential and time [8].
Gas nitriding is the most commonly used in industrial technology. Depending on the nitriding atmosphere used, gas nitiriding is distinguished into one-component (ammonia) or two-component nitriding (ammonia and dissociated ammonia or ammonia and nitrogen) [9].
3 Methods of assessing the nitrided layer
3.1 Eddy current and magnetic Barkhausen noise method
In the works [2,3,4,5], attempts were made to use the eddy current method to assess the thickness of the nitrided layers. Samples made of 38 HMJ and WCL steel were tested. The dependence of the measuring device signal on the thickness of nitrided layers on the previously prepared samples was investigated. Wirotest measuring equipment was used for the tests, together with sensors with different magnetization current frequencies. The conducted research has shown that this method can be successfully used to assess the thickness of the nitrided layer. A sensor was used to measure the thickness of the nitrided layer with a magnetization current frequency of 3.4 kHz. For both 38 HMJ and WCL steels, a high correlation was obtained between the indications of the measuring instrument and the thickness of the nitrided layer (R 2 coefficient values at the level of 0.93–0.99). The parameters of the performed nitriding processes influenced the level of correlation, but in all cases, the indications of the measuring instrument increased along with the increase in the thickness of the nitrided layer (Figure 2).
![Figure 2
The relationship between the thickness of the nitrided layer on 38 HMJ steel and the mean readings of the Wirotest 03 instrument [5].](/document/doi/10.1515/eng-2022-0401/asset/graphic/j_eng-2022-0401_fig_002.jpg)
The relationship between the thickness of the nitrided layer on 38 HMJ steel and the mean readings of the Wirotest 03 instrument [5].
In the literature, it is possible to write works in which the Barkhausen noise method were used for the assessment of nitrided layers. Stupakov et al. [6] state that the classical RMS parameter demonstrated the best sensitivity to growing thickness of the hardened surface layer. The commercial device with the small attachable sensor was able to estimate the nitrided case of up to 100–150 µm thickness.
3.2 Ultrasonic method
Ultrasonic method waves have great potential in the assessment of nitrided layers. In particular, Rayleigh waves and Love waves. Unfortunately, there are very few studies on this subject. Belahcene et al. [7] used surface waves of different propagation depths. The authors investigated an aircraft engine bearing a nitrided surface. A measuring system with two heads was used for the tests (Figure 3). The distance between the transmitter and receiver was constant. Waves with frequencies from 3 to 12 MHz were introduced, which resulted in a different depth of wave penetration from 0.25 to 0.85 mm.
![Figure 3
The measuring system on the bearing surface [7].](/document/doi/10.1515/eng-2022-0401/asset/graphic/j_eng-2022-0401_fig_003.jpg)
The measuring system on the bearing surface [7].
According to the authors, the thickness of the layer is defined by the wavelength above which the plateau is observed in the variability of wave propagation. The works undertaken by the authors were not continued.
Surface waves were also used by Samolczyk and Baer [10]. In this case, the layer thickness was determined on the basis of the determined calibration curve. To determine the calibration curve, samples of WCL steel subjected to ion nitriding at a temperature of 500°C were prepared. USLT 2000 flaw detector and 4 MHz MBW 90-4E heads were used for the measurements. The calibration curve was based on changes in the velocity of the surface wave. In this case also, the authors did not continue their work.
The use of the Love wave should provide great possibilities in the assessment of nitrided layers. This wave propagates in the layers created on the surfaces of objects. This wave is highly dispersive, which means that its speed depends on the change in material properties [11,12,13]. One of the methods of its production consists in the use of a blade head [14], laser [15] or Hertzian’s head [16]. In the experiment described in this article, a blade head was used.
4 Experimental methods
4.1 Purpose and scope of the experiment
The aim of the experiment was to check the sensitivity of changes in the parameters of the ultrasonic wave to the presence of the nitrided coating. The scope of the experiment included the preparation of samples on which the ultrasonic wave parameters were measured. Then, the samples were subjected to the nitriding process. After forming the nitriding layer, measurements of the ultrasonic wave parameters were performed. The parameters of the wave on the samples before and after nitriding were compared.
4.2 Research object
Samples from steel 38 HMJ were used for the tests (Figure 4). It is a structural chromium-molybdenum steel intended for nitriding. The chemical composition of steel is given in Table 1.

The samples used during the tests are marked with letters A–F.
Chemical composition of steel 38 HMJ [17]
| C | Si | Mn | Cr | Mo | Al | Ni | V | W | S | P |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.35–0.42 | 0.17–0.37 | 0.3–0.6 | 1.35–1.65 | 0.15–0.25 | 0.7–1.1 | max 0.25 | max 0.05 | max 0.2 | max 0.025 | max 0.025 |
The gas nitriding process in an ammonia atmosphere lasted 19 h at a temperature of 550°C with a nitrogen potential N p of 3.0. The view of the samples after nitriding is shown in Figure 5.

View of samples after the nitriding process.
4.3 Measuring system and methodology of research
An ultrasonic flaw detector UMT-12 and a UZIP blade head with a frequency of 4 MHz were used to perform the measurements (Figure 6). The head consists of two transducers. One is the transmitter and the other is the receiver of the wave. The wave is introduced into the object and picked up by blades connected to the transducers.

Blade head UZIP with a frequency of 4 MHz.
In the first stage of the research, the probe was applied to the non-nitrided samples. The ultrasonic wave that reached the receiver is shown in Figure 7. The pulse of the received wave was subjected to the Fourier transform and the amplitude–frequency spectrum was obtained (Figure 8).

Ultrasonic pulse in the time domain.

Ultrasonic pulse in the frequency domain.
Three ultrasonic parameters were analyzed during the research – time of wave propagation t, dominant frequency of the spectrum f max and bandwidth B (Figure 9).

Parameters of the amplitude–frequency spectrum: f max – dominant frequency of the spectrum (MHz) and B – bandwidth (MHz).
Each sample has two flat surfaces (top – 1 and bottom – 2). An ultrasonic head was attached to each of them and the measurements were repeated ten times. The measurements were made with the head blades with spacing of 50 mm and with the constant pressure of the head to the surface, which was provided by a constant mass weight. A total of 120 measurements were performed on the samples before nitriding and 120 measurements on the samples after nitriding. In each application, three parameters of the ultrasonic wave were measured.
4.4 Results of research
Detailed results of measurements for sample A before and after nitriding are presented in Tables 2 and 3. Based on the obtained results, their mean value
Results for sample A before nitriding
| No. | Top side (A1) | Bottom side (A2) | ||||
|---|---|---|---|---|---|---|
| t (μs) | f max (MHz) | B (MHz) | t (μs) | f max (MHz) | B (MHz) | |
| 1 | 39.50 | 3.80 | 1.73 | 39.50 | 3.80 | 1.83 |
| 2 | 39.50 | 3.73 | 1.76 | 39.50 | 3.80 | 1.73 |
| 3 | 39.50 | 3.80 | 1.83 | 39.50 | 3.80 | 1.76 |
| 4 | 39.50 | 3.80 | 1.83 | 39.50 | 3.80 | 1.83 |
| 5 | 39.50 | 3.73 | 1.76 | 39.50 | 3.87 | 1.69 |
| 6 | 39.50 | 3.76 | 1.76 | 39.50 | 3.76 | 1.76 |
| 7 | 39.50 | 3.73 | 1.83 | 39.50 | 3.73 | 1.83 |
| 8 | 39.50 | 3.80 | 1.83 | 39.50 | 3.80 | 1.69 |
| 9 | 39.50 | 3.73 | 1.83 | 39.50 | 3.73 | 1.83 |
| 10 | 39.50 | 3.80 | 1.76 | 39.50 | 3.80 | 1.83 |
|
|
39.50 | 3.77 | 1.79 | 39.50 | 3.79 | 1.78 |
| s | 0 | 0.035 | 0.041 | 0 | 0.041 | 0.060 |
Results for sample A after nitriding
| No. | Top side (A1) | Bottom side (A2) | ||||
|---|---|---|---|---|---|---|
| t (μs) | f max (MHz) | B (MHz) | t (μs) | f max (MHz) | B (MHz) | |
| 1 | 22.94 | 3.73 | 1.76 | 22.94 | 3.66 | 1.76 |
| 2 | 22.94 | 3.66 | 1.83 | 22.94 | 3.73 | 1.76 |
| 3 | 22.94 | 3.73 | 1.83 | 22.94 | 3.73 | 1.73 |
| 4 | 22.94 | 3.73 | 1.83 | 22.94 | 3.66 | 1.90 |
| 5 | 22.94 | 3.73 | 1.90 | 22.94 | 3.73 | 1.83 |
| 6 | 22.94 | 3.73 | 1.83 | 22.94 | 3.66 | 1.76 |
| 7 | 22.94 | 3.80 | 1.76 | 22.94 | 3.73 | 1.76 |
| 8 | 22.94 | 3.73 | 1.76 | 22.94 | 3.73 | 1.69 |
| 9 | 22.94 | 3.80 | 1.76 | 22.94 | 3.73 | 1.69 |
| 10 | 22.94 | 3.80 | 1.76 | 22.94 | 3.73 | 1.76 |
|
|
22.94 | 3.74 | 1.80 | 22.94 | 3.71 | 1.76 |
| s | 0 | 0.044 | 0.049 | 0 | 0.034 | 0.062 |
Mean values and standard deviations of all samples before nitriding
| Sample | Top side (1) | Bottom side (2) | |||||
|---|---|---|---|---|---|---|---|
| t (μs) | f max (MHz) | B (MHz) | t (μs) | f max (MHz) | B (MHz) | ||
| A |
|
39.50 | 3.77 | 1.79 | 39.50 | 3.79 | 1.78 |
| s | 0 | 0.035 | 0.041 | 0 | 0.041 | 0.060 | |
| B |
|
39.50 | 3.74 | 1.75 | 39.50 | 3.75 | 1.75 |
| s | 0 | 0.062 | 0.090 | 0 | 0.023 | 0.097 | |
| C |
|
39.50 | 3.76 | 1.73 | 39.50 | 3.76 | 1.71 |
| s | 0 | 0.027 | 0.048 | 0 | 0.029 | 0.056 | |
| D |
|
39.50 | 3.73 | 1.73 | 39.50 | 3.76 | 1.70 |
| s | 0 | 0.043 | 0.057 | 0 | 0.047 | 0.044 | |
| E |
|
39.50 | 3.75 | 1.76 | 39.50 | 3.77 | 1.73 |
| s | 0 | 0.034 | 0.076 | 0 | 0.055 | 0.046 | |
| F |
|
39.50 | 3.74 | 1.72 | 39.50 | 3.77 | 1.75 |
| s | 0 | 0.035 | 0.052 | 0 | 0.046 | 0.055 | |
Mean values and standard deviations of all samples after nitriding
| Sample | Top side (1) | Bottom side (2) | |||||
|---|---|---|---|---|---|---|---|
| t (μs) | f max (MHz) | B (MHz) | t (μs) | f max (MHz) | B (MHz) | ||
| A |
|
22.94 | 3.74 | 1.80 | 22.94 | 3.71 | 1.76 |
| s | 0 | 0.044 | 0.049 | 0 | 0.034 | 0.062 | |
| B |
|
22.94 | 3.72 | 1.75 | 22.94 | 3.73 | 1.78 |
| s | 0 | 0.040 | 0.090 | 0 | 0.044 | 0.034 | |
| C |
|
22.94 | 3.74 | 1.76 | 22.94 | 3.74 | 1.79 |
| s | 0 | 0.048 | 0.034 | 0 | 0.056 | 0.070 | |
| D |
|
22.94 | 3.73 | 1.77 | 22.94 | 3.75 | 1.77 |
| s | 0 | 0.053 | 0.064 | 0 | 0.044 | 0.040 | |
| E |
|
22.94 | 3.72 | 1.79 | 22.94 | 3.73 | 1.79 |
| s | 0 | 0.046 | 0.049 | 0 | 0.034 | 0.049 | |
| F |
|
22.94 | 3.73 | 1.80 | 22.94 | 3.74 | 1.79 |
| s | 0 | 0.043 | 0.049 | 0 | 0.035 | 0.049 | |
The summary of the mean values for the samples A–F (sides 1 and 2) before and after nitriding is shown in Figures 10–12, respectively, for the ultrasonic wave propagation time t, dominant frequency of the spectrum f max and bandwidth B.

The summary of the mean values for the samples A–F (sides 1 and 2) before and after nitriding for the ultrasonic wave propagation time t.

The summary of the mean values for the samples A–F (sides 1 and 2) before and after nitriding for the dominant frequency of the spectrum f max.

The summary of the mean values for the samples A–F (sides 1 and 2) before and after nitriding for the bandwidth B.
4.5 Analysis of research
Comparing the results of the measurement of the mean values for the ultrasonic wave propagation time t for the samples before nitriding, it can be seen that these values are identical. The mean values are 36.50 µs and are the same for all samples A through F. The standard deviation is 0.0. For the same samples (before nitriding), the mean dominant frequency of the spectrum f max values are also very similar, ranging from 3.73 to 3.79 MHz with a standard deviation of 0.023–0.062 MHz. The standard deviation of 0.062 MHz is only 1.6% of the value of 3.73 MHz. It is also similar to the average values of the bandwidth B, whose values ranged from 1.70 to 1.79 MHz, with a standard deviation of 0.041–0.097. The standard deviation of 0.097 MHz is 5.7% of the value of 1.70 MHz. It can be concluded that in the samples before nitriding, the dispersion of the values of all three parameters of the ultrasonic wave is small. The values are stable and repeatable.
After the nitriding process was performed, the values of the measured ultrasonic wave parameters changed. The mean values of ultrasonic wave propagation time t are 22.94 µs and are the same for all samples A through F. The standard deviation is 0.0. The mean dominant frequency of the spectrum f max is from 3.71 to 3.75 MHz with a standard deviation of 0.034–0.056 MHz. The standard deviation of 0.056 MHz is only 1.5% of the value of 3.71 MHz. The average values of the bandwidth B, is from 1.75 to 1.80 MHz, with a standard deviation of 0.034–0.090. The standard deviation of 0.090 MHz is 5.1% of the value of 1.75 MHz. It can be concluded that the dispersion of the values of all three parameters of the ultrasonic wave in the samples after nitriding is small. The values are stable and repeatable, similar to the samples before nitriding.
The stability and reproducibility of the results of all three parameters in the samples before and after nitriding means that the samples were homogeneous in terms of ultrasonic wave propagation in them. The homogeneity was before and after the nitriding process.
While comparing the differences in the values of individual parameters in the samples before and after nitriding, it should be noted that the average wave propagation time t decreased from 39.50 to 22.94, by as much as 16.56 µs. The reduction in the wave transit time, for the same length of its path, means that there was an increase in the wave propagation speed in the samples after nitriding. The increase in velocity, therefore, had to be due to the presence of a nitrided layer. Thus, it should be stated that the wave velocity is sensitive to the presence of the nitrided layer.
In the case of the mean dominant frequency of the spectrum f max value, the changes are not as significant as in the case of the ultrasonic wave propagation time t. However, it can be observed that for each of the 12 surfaces (from A1 to F2), the dominant frequency of the spectrum f max values on the samples after nitriding are lower than the values on the samples before nitriding. This can be seen very clearly in Figure 11.
A similar relationship can also be indicated in the values of the bandwidth B. Changes in the value of this parameter on the samples after nitriding are not so significant; however, on the surface after nitriding (except for A2 and B1 surfaces), the value of this parameter is higher than in the case of surfaces before nitriding. This relationship is clearly visible in Figure 12.
5 Conclusion
The obtained results show the high repeatability of the ultrasonic wave parameters propagating values in the samples without the nitrided layer and in the samples with the nitrided layer. The value of one of the parameters changed significantly after the formation of the nitrided layer. This parameter is the wave propagation time which results from the change in the velocity of the wave. All samples were subjected to the same nitriding process, so the layer produced in them was identical in terms of thickness. Thus, the presence of this layer caused an identical change in the wave propagation time in all samples, i.e., on all 12 surfaces.
The conducted research was reconnaissance and initial. The observed changes in the wave propagation time due to the presence of the nitrided layer allowed for further research to be planned. They should be aimed at measuring the wave propagation time in samples with different nitrided layer thicknesses.
-
Funding information: Research work was financed by the project 0414/SBAD/3612.
-
Conflict of interest: Author state no conflict interest.
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This work is licensed under the Creative Commons Attribution 4.0 International License.
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- Effect of adverse slope on performance of USBR II stilling basin
- Shear capacity of reinforced concrete beams with recycled steel fibers
- Extracting oil from oil shale using internal distillation (in situ retorting)
- Influence of recycling waste hardened mortar and ceramic rubbish on the properties of flowable fill material
- Rehabilitation of reinforced concrete deep beams by near-surface-mounted steel reinforcement
- Impact of waste materials (glass powder and silica fume) on features of high-strength concrete
- Studying pandemic effects and mitigation measures on management of construction projects: Najaf City as a case study
- Design and implementation of a frequency reconfigurable antenna using PIN switch for sub-6 GHz applications
- Average monthly recharge, surface runoff, and actual evapotranspiration estimation using WetSpass-M model in Low Folded Zone, Iraq
- Simple function to find base pressure under triangular and trapezoidal footing with two eccentric loads
- Assessment of ALINEA method performance at different loop detector locations using field data and micro-simulation modeling via AIMSUN
- Special Issue: AESMT-5 - Part I
- Experimental and theoretical investigation of the structural behavior of reinforced glulam wooden members by NSM steel bars and shear reinforcement CFRP sheet
- Improving the fatigue life of composite by using multiwall carbon nanotubes
- A comparative study to solve fractional initial value problems in discrete domain
- Assessing strength properties of stabilized soils using dynamic cone penetrometer test
- Investigating traffic characteristics for merging sections in Iraq
- Enhancement of flexural behavior of hybrid flat slab by using SIFCON
- The main impacts of a managed aquifer recharge using AHP-weighted overlay analysis based on GIS in the eastern Wasit province, Iraq
Articles in the same Issue
- Regular Articles
- Design optimization of a 4-bar exoskeleton with natural trajectories using unique gait-based synthesis approach
- Technical review of supervised machine learning studies and potential implementation to identify herbal plant dataset
- Effect of ECAP die angle and route type on the experimental evolution, crystallographic texture, and mechanical properties of pure magnesium
- Design and characteristics of two-dimensional piezoelectric nanogenerators
- Hybrid and cognitive digital twins for the process industry
- Discharge predicted in compound channels using adaptive neuro-fuzzy inference system (ANFIS)
- Human factors in aviation: Fatigue management in ramp workers
- LLDPE matrix with LDPE and UV stabilizer additive to evaluate the interface adhesion impact on the thermal and mechanical degradation
- Dislocated time sequences – deep neural network for broken bearing diagnosis
- Estimation method of corrosion current density of RC elements
- A computational iterative design method for bend-twist deformation in composite ship propeller blades for thrusters
- Compressive forces influence on the vibrations of double beams
- Research on dynamical properties of a three-wheeled electric vehicle from the point of view of driving safety
- Risk management based on the best value approach and its application in conditions of the Czech Republic
- Effect of openings on simply supported reinforced concrete skew slabs using finite element method
- Experimental and simulation study on a rooftop vertical-axis wind turbine
- Rehabilitation of overload-damaged reinforced concrete columns using ultra-high-performance fiber-reinforced concrete
- Performance of a horizontal well in a bounded anisotropic reservoir: Part II: Performance analysis of well length and reservoir geometry
- Effect of chloride concentration on the corrosion resistance of pure Zn metal in a 0.0626 M H2SO4 solution
- Numerical and experimental analysis of the heat transfer process in a railway disc brake tested on a dynamometer stand
- Design parameters and mechanical efficiency of jet wind turbine under high wind speed conditions
- Architectural modeling of data warehouse and analytic business intelligence for Bedstead manufacturers
- Influence of nano chromium addition on the corrosion and erosion–corrosion behavior of cupronickel 70/30 alloy in seawater
- Evaluating hydraulic parameters in clays based on in situ tests
- Optimization of railway entry and exit transition curves
- Daily load curve prediction for Jordan based on statistical techniques
- Review Articles
- A review of rutting in asphalt concrete pavement
- Powered education based on Metaverse: Pre- and post-COVID comprehensive review
- A review of safety test methods for new car assessment program in Southeast Asian countries
- Communication
- StarCrete: A starch-based biocomposite for off-world construction
- Special Issue: Transport 2022 - Part I
- Analysis and assessment of the human factor as a cause of occurrence of selected railway accidents and incidents
- Testing the way of driving a vehicle in real road conditions
- Research of dynamic phenomena in a model engine stand
- Testing the relationship between the technical condition of motorcycle shock absorbers determined on the diagnostic line and their characteristics
- Retrospective analysis of the data concerning inspections of vehicles with adaptive devices
- Analysis of the operating parameters of electric, hybrid, and conventional vehicles on different types of roads
- Special Issue: 49th KKBN - Part II
- Influence of a thin dielectric layer on resonance frequencies of square SRR metasurface operating in THz band
- Influence of the presence of a nitrided layer on changes in the ultrasonic wave parameters
- Special Issue: ICRTEEC - 2021 - Part III
- Reverse droop control strategy with virtual resistance for low-voltage microgrid with multiple distributed generation sources
- Special Issue: AESMT-2 - Part II
- Waste ceramic as partial replacement for sand in integral waterproof concrete: The durability against sulfate attack of certain properties
- Assessment of Manning coefficient for Dujila Canal, Wasit/-Iraq
- Special Issue: AESMT-3 - Part I
- Modulation and performance of synchronous demodulation for speech signal detection and dialect intelligibility
- Seismic evaluation cylindrical concrete shells
- Investigating the role of different stabilizers of PVCs by using a torque rheometer
- Investigation of high-turbidity tap water problem in Najaf governorate/middle of Iraq
- Experimental and numerical evaluation of tire rubber powder effectiveness for reducing seepage rate in earth dams
- Enhancement of air conditioning system using direct evaporative cooling: Experimental and theoretical investigation
- Assessment for behavior of axially loaded reinforced concrete columns strengthened by different patterns of steel-framed jacket
- Novel graph for an appropriate cross section and length for cantilever RC beams
- Discharge coefficient and energy dissipation on stepped weir
- Numerical study of the fluid flow and heat transfer in a finned heat sink using Ansys Icepak
- Integration of numerical models to simulate 2D hydrodynamic/water quality model of contaminant concentration in Shatt Al-Arab River with WRDB calibration tools
- Study of the behavior of reactive powder concrete RC deep beams by strengthening shear using near-surface mounted CFRP bars
- The nonlinear analysis of reactive powder concrete effectiveness in shear for reinforced concrete deep beams
- Activated carbon from sugarcane as an efficient adsorbent for phenol from petroleum refinery wastewater: Equilibrium, kinetic, and thermodynamic study
- Structural behavior of concrete filled double-skin PVC tubular columns confined by plain PVC sockets
- Probabilistic derivation of droplet velocity using quadrature method of moments
- A study of characteristics of man-made lightweight aggregate and lightweight concrete made from expanded polystyrene (eps) and cement mortar
- Effect of waste materials on soil properties
- Experimental investigation of electrode wear assessment in the EDM process using image processing technique
- Punching shear of reinforced concrete slabs bonded with reactive powder after exposure to fire
- Deep learning model for intrusion detection system utilizing convolution neural network
- Improvement of CBR of gypsum subgrade soil by cement kiln dust and granulated blast-furnace slag
- Investigation of effect lengths and angles of the control devices below the hydraulic structure
- Finite element analysis for built-up steel beam with extended plate connected by bolts
- Finite element analysis and retrofit of the existing reinforced concrete columns in Iraqi schools by using CFRP as confining technique
- Performing laboratory study of the behavior of reactive powder concrete on the shear of RC deep beams by the drilling core test
- Special Issue: AESMT-4 - Part I
- Depletion zones of groundwater resources in the Southwest Desert of Iraq
- A case study of T-beams with hybrid section shear characteristics of reactive powder concrete
- Feasibility studies and their effects on the success or failure of investment projects. “Najaf governorate as a model”
- Optimizing and coordinating the location of raw material suitable for cement manufacturing in Wasit Governorate, Iraq
- Effect of the 40-PPI copper foam layer height on the solar cooker performance
- Identification and investigation of corrosion behavior of electroless composite coating on steel substrate
- Improvement in the California bearing ratio of subbase soil by recycled asphalt pavement and cement
- Some properties of thermal insulating cement mortar using Ponza aggregate
- Assessment of the impacts of land use/land cover change on water resources in the Diyala River, Iraq
- Effect of varied waste concrete ratios on the mechanical properties of polymer concrete
- Effect of adverse slope on performance of USBR II stilling basin
- Shear capacity of reinforced concrete beams with recycled steel fibers
- Extracting oil from oil shale using internal distillation (in situ retorting)
- Influence of recycling waste hardened mortar and ceramic rubbish on the properties of flowable fill material
- Rehabilitation of reinforced concrete deep beams by near-surface-mounted steel reinforcement
- Impact of waste materials (glass powder and silica fume) on features of high-strength concrete
- Studying pandemic effects and mitigation measures on management of construction projects: Najaf City as a case study
- Design and implementation of a frequency reconfigurable antenna using PIN switch for sub-6 GHz applications
- Average monthly recharge, surface runoff, and actual evapotranspiration estimation using WetSpass-M model in Low Folded Zone, Iraq
- Simple function to find base pressure under triangular and trapezoidal footing with two eccentric loads
- Assessment of ALINEA method performance at different loop detector locations using field data and micro-simulation modeling via AIMSUN
- Special Issue: AESMT-5 - Part I
- Experimental and theoretical investigation of the structural behavior of reinforced glulam wooden members by NSM steel bars and shear reinforcement CFRP sheet
- Improving the fatigue life of composite by using multiwall carbon nanotubes
- A comparative study to solve fractional initial value problems in discrete domain
- Assessing strength properties of stabilized soils using dynamic cone penetrometer test
- Investigating traffic characteristics for merging sections in Iraq
- Enhancement of flexural behavior of hybrid flat slab by using SIFCON
- The main impacts of a managed aquifer recharge using AHP-weighted overlay analysis based on GIS in the eastern Wasit province, Iraq