Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Ground penetrating radar


Effect of Some Vegetables (Carrots, Onion, Parsley, and Red radish) on Corrosion Behavior of Amalgam Dental Filling in Artificial Saliva

Slafa Ismael Ibrahim; Nemir Ahmed Al-Azzawi; Shatha Mizhir Hasan; Hussein H. Karim; Ammar M. M. Al-Qaissi; Ahmed Chyad Kadhim; Mehdi Munshid Shellal; Sinan Majid Abdul Satar; Wahid S. Mohammad; Assad Oda Jassim; Khalid salem Shibib; Karema Assi Hamad; Haqui Ismael Qatta; Hayder Hadi Abbas; Kanaan A. Jalal; Hussain Kassim Ahmad; Makram A. Fakhri; Mohanned M.H. AL-Khafaji; Hussam Lefta Alwan; Baraa M.H. Albaghdadi

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1216-1226

This work involves study corrosion behavior of amalgam in presence of some vegetables including (Carrots, Onion, Parsley, and Red radish) which were chosen because they require mastication process by teeth and taking enough time that make them in a contact with amalgams filling in artificial saliva.
The corrosion parameters were interpreted in artificial saliva at pH (5.1) and (37±1oC) by adding (50 ml/l) of vegetable juice to artificial saliva, which involve corrosion potential (Ecorr), corrosion current density (icorr), Cathodic and anodic Tafel slopes (bc & ba ) and polarization resistance, the results of (Ecorr) and (icorr) indicate that the medium of saliva and (50 ml/l) onion is more corrosive than the other media. Cathodic and anodic tafel slopes were used to calculate the polarization resistance (Rp) to know which medium more effective on amalgam of dental filling, this study shows that the increasing in polarization resistance through the decreasing in corrosion rate values, the results of (Rp) take the sequence:
Rp:( saliva+ parsley) >( saliva+ red radish)> saliva>(saliva+ carrots) >(saliva+ onion).
While corrosion rates (CR ) take the sequence:
CR: (Saliva+Parsley) Keywords

Amalgam
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Corrosion in saliva
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Potentiostatic measurements

Evaluation of Road Pavement and Subsurface Defects Mapping Using Ground Penetrating Radar (GPR)

Hussein H. Karim; Ammar M. M. Al-Qaissi

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1240-1250

GPR is frequently used for inspection road pavement (thickness estimation, damage detection and diagnosis), so this technique was selected for this purpose. Three types of antennas were used: 250, 500 and 800 MHz. In the field, the survey has been carried out on one lanes paved road about 1250 m long inside University of Technology Campus. The obtained radargrams raw data were analyzed using sophisticated softwares to determine asphalt and concrete layers thicknesses for base and subase. Several inspections have been carried out to study the effect of changing the operating setting parameters of GPR on the data accuracy and interpretation for paved roads damages and the pavement layers thicknesses. The interpretation results, using 250 MHz antenna, showed the possibility of identifying buried plastic pipe and the flexible pavement layer. While the rigid pavement layer is unresolved. With 500 MHz antenna, the plastic pipe, rigid pavement, steel reinforcement bars and joint sheet cork appeared clearly. It was found that the short type of the Max. Time Window using antenna 800 MHz is the most suitable for detecting some radar anomalies (plastic pipe, cork sheet and reinforcement bars and pavement thickness) which were more clearly defined. No change is noticed on radargrams when applying different point intervals. The suitable radar wave velocity for estimating the thicknesses of the surface, binder and rigid pavement layers were 80, 160 and 180 m/ns respectively. While, the surface cracks were undetectable with 800 MHz antenna but the cause of such crack was identified. Correlation GPR thickness data with the asphalt core data, states that the error of the thickness measurements from GPR resulted in average deviation (the percentage error) of about 4%.

Assessment of the Accuracy of Road Flexible and Rigid Pavement Layers Using GPR

Hussein H. Karim; Ammar M. M. Al-Qaissi

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 788-799

Ground Penetrating Radar (GPR) is frequently used in pavement engineering for road pavement inspection. The main objective of this work is to validate nondestructive, quick and powerful measurements using GPR for assessment of flexible and rigid pavement thicknesses and detection of rebars and joints within the rigid pavement. To achieve this work, in-situ simulation model (1.2 m 1.2 m in dimension), consists of three layers (sub-base, flexible and rigid pavement), was made and surveyed by GPR using three antennas (250, 500 and 800 MHz). The interpretation results of 250 MHz antenna identify and assign the flexible pavement as one layer without identifying the rigid pavement layer. With the 500 MHz antenna, the flexible pavement appeared as one layer with identifying the rigid pavement boundaries. While using 800 MHz antenna, both flexible pavement and rigid pavement layers were clearly identified as in the in-situ simulation model. Therefore, the 250 and 500 MHz antennas have much more penetration, but much lower resolution. Besides, rebars and joints were clearly appeared in both 500 and 800 MHz antenna. By correlating in-situ model with radar GPR data, the results show thickness deviations (percentage error) on the order of 1% for surface layer and about 2% for both binder and rigid layers. Applying 500 and 800 MHz antennas perpendicular to steel reinforcement within rigid pavement, the rebars (with dielectric constant equal to 13.6 with velocity equal to 8.1 cm/ns) and joints (with width 0.025 m) appeared in the radargram. From the precise calculation of thickness, it can be concluded that an excellent correlation between field model and radar data.

GPR Data Simulation for Detecting Subsurface Bodies

Haidar A. N. Al-dami; Hussein H. Karim

Engineering and Technology Journal, 2012, Volume 30, Issue 15, Pages 2678-2693

Ground-penetrating radar (GPR) technique was used at University of Technology-Baghdad, as a non destructive, quick, low cost and powerful technique in detecting any change in the constituents of subsurface as materials which can be consequently applied in urban and constructed areas. The main objectives of this study are: to simulate GPR data obtained by 250 and 500 MHz antennas for shallow engineering investigation by detecting different subsurface bodies. A simulation is made for GPR data with different geometric buried bodies and located at different depth. Before processing, most of the raw data of radargram do not reflect the presence of the buried bodies. But after processing by using suitable filters and other interpretation tool parameters, many of the investigated subsurface bodies and structures appeared clearly. It is found from this study that the degree of clarity of the buried bodies do not depend on the higher value of dielectric constant of the body, but it depends on the contrast between the body and the host medium. Thus the body with low dielectric constant appears more clear than that with higher dielectric constant, when they are at the same depth. Most of the buried bodies appeared on GPR radargrams using the medium frequencies. The best detecting depth are 1.5 m to 1 m for 250 and 500 MHz antennas respectively.

Non-Destructive Testing of Concrete Structures Using GPR Technique with an Intermediate Frequency Antennas

Hussein H. Karim; Haidar A. N. Al-dami

Engineering and Technology Journal, 2012, Volume 30, Issue 14, Pages 2443-2452

Ground penetrating radar (GPR) is a geophysical technique of imaging the
subsurface structures at high resolution and it is a non-destructive technique can
consequently be applied in many civil engineering fields and sensitive
environments. The amount of data collected however can be very large and take
a significant level of subjective experience to interpret. This study focuses upon
the ability of using the GPR with 250 MHz and 500 MHz antennas (intermediate
frequencies) to investigate the reinforced concrete to indicate the quantity of
steel bars and their configurations in the concrete constructed in the hidden
mensurations. The recent study shows the ability of using the intermediate
frequency antennas for such fields.