Print ISSN: 1681-6900

Online ISSN: 2412-0758



Research Paper

Performance of Geopolymer Concrete Exposed to Freezing and Thawing Cycles

Mohammed H. Shamsa; Basil S. Al-Shathr; Tareq S. al-Attar

Engineering and Technology Journal, 2019, Volume 37, Issue 3A, Pages 78-84
DOI: 10.30684/etj.37.3A.1

In this study, the effect of rapid freezing and thawing (ASTM C666 – procedure A) on three different types of Geopolymer concrete studied using three types of pozzolanic material: fly ash, metakaolin and ground granulated blast furnace slag (GGBFS). The Geopolymer concrete was prepared using 400 kg of the pozzolanic material with alkaline liquid prepared at 8 molar concentration with normal fine and coarse aggregates. The ratio of alkaline to fly ash and GGBFS was 1.5: 1 and for metakaolin was 2: 1 for workability and compressive strength requirements. Specimens (100 × 100 × 400) mm were exposed to 100, 200 and 300 cycles of freezing and thawing. The decrease in measured compressive strength was (23, 43, and 26%) for Fly ash, metakaolin and GGBFS respectively. The investigated types of concrete showed good resistance to freezing and thawing. The durability factor of these types was (77%, 68%, and 81%) for fly ash, metakaolin, and GGBFS respectively.

Design of Double Notch Band Half-Elliptical Shape Reconfigurable Antenna for UWB Applications

Haydar M. Al-Tamimi; Salah M. O.

Engineering and Technology Journal, 2019, Volume 37, Issue 3A, Pages 85-89
DOI: 10.30684/etj.37.3A.2

A compact ultra-wideband (UWB) reconfigurable antenna with dual band-notched properties is presented in this paper. The dual notch band half – elliptical reconfigurable antenna is fed by (50 Ω) microstrip feed lines and it is printed above an FR-4 substrates (32 × 32.6) mm2 dimensions. This dual band notched characteristic is accomplished by embedding two crossing U-shaped slot in the half-elliptical radiating patch of the proposed reconfigurable antenna. The modeling procedure and performance evaluation of the presented antenna was achieved by using the electromagnetic simulator software, (CST) Computer Simulation Technology. The measured bandwidth of the presented antenna for (VSWR < 2) spans 2.6 GHz to 12 GHz, which covers the entire UWB band of 3.1 GHz to 10.6 GHz, with a controlling dual notched band (VSWR > 2) in 3.5 GHz and 5.2 GHz. The presented antenna is appropriate for UWB applications with another benefits of reduces the interference effect with the wireless local area network (WLAN) systems that operating in 5.15–5.35 GHz band (IEEE 802.11a), as well as reducing the interference effect with the Worldwide Interoperability for Microwave Access (WiMAX) application, which operates in 3.5 GHz band (IEEE 802.16e). The parameters that affect the efficiency of the antenna as regards to its frequency domain and radiation pattern qualities are studied.

A Survey on Deceptive Detection Systems and Technologies

Harith H. Thannoon; Wissam H. Ali; Ivan A. Hashim

Engineering and Technology Journal, 2019, Volume 37, Issue 3A, Pages 90-95
DOI: 10.30684/etj.37.3A.3

There are many types of indicators that have been proven to be useful clues for deceptive detection techniques, and most of this indicators that have been presented and proven by psychology to be signs of lying. This paper presents a survey of most popular deceptive detection systems. Many techniques for lie detection have been presented by researchers; most of them are reviewed in this paper. This study focus on the algorithms, which are presented in some pervious work, and how the database has been collected for each technique, furthermore explain the adopted cues for each deception detection technique. The accuracy of each proposed technique is included in this paper, then this study shows the advantage and disadvantages for each deception system with the useful and robust cues here.

Analysing Some Mechanical Properties of Cinnamon Powder Reinforced with Polymeric Materials Used in Dental Application

Ahamed M. AlGhabban; Reem A. Mohammed; Jumaah R. Mahmood

Engineering and Technology Journal, 2019, Volume 37, Issue 3A, Pages 96-105
DOI: 10.30684/etj.37.3A.4

In the dentures industry, materials must be chosen to have good mechanical properties in order to resist the conditions that may occur in the mouth. A study was conducted to assess tensile strength, elasticity coefficient, elongation, flexural strength, flexural modulus with impact properties of poly methyl methacrylate resin as matrix strengthened with cinnamon powder and also analysing these mechanical properties by using (OriginLab) software program. The samples of Poly Methyl methacrylate bio composites which containing 2%, 4%, 6%, and 8% weight fractions of cinnamon powder and an unfilled as control sample were fabricated using “hand lay up” method. The results indicate that the addition of 8% weight fraction cinnamon powder into Poly Methyl methacrylate resin improved of ultimate tensile strength, modulus elasticity ,flexural strength, flexural modulus (62 MPa, 3.7 GPa, 96 MPa, 6.4 GPa) respectively, compared with the values of pure Poly Methyl methacrylate (51 MPa, 1.5 GPa, 78MPa, 2.0 GPa) respectively. Also can be noted that the elongation at break values decreases with an increase in weight fractions of filler, where the sample (Poly Methyl methacrylate +2% cinnamon) has the best value for elongation compared with samples reinforced (4%, 6% and 8% wt). The impact strength results observe the maximum value was present in the sample (Poly Methyl methacrylate+6% cinnamon). From the results, descriptive, One Way ANOVA statistical analysis and means comparison by used (Scheffe test and Tukey test) for all mechanical properties indicated, turns out if Sig equals 1 shows that the variance in mean is significant at the level of 0.05, whereas Sig is 0 designates that the mean variance is not significant at the level 0.05.

Design of n-Bit Adder without Applying Binary to Quaternary Conversion

Walaa MH. Khalaf; Dhafer Zaghar; Kadhum Al-majdi

Engineering and Technology Journal, 2019, Volume 37, Issue 3A, Pages 106-111
DOI: 10.30684/etj.37.3A.5

Microprocessor has been considered as most important part in ICs manufacturing and making progress since more than 50 years, so increasing microprocessor speed is paid attention in all technologies. ALU is known as the slowest part in microprocessor because of the ripple carry, nowadays microprocessor uses 8-uints as pipeline, each one has 8-bits for implementing 64-bit, working in this form has been captured the microprocessor development and limited its speed for all its computations. Parallel processing and high speed ICs always trying to increase this speed but unfortunately it remains limited. The contemporary solution for increasing microprocessors speed is the Multiple Valued Logic (MVL) technology that will reduce the 8-bits to 4-qbits, this paper proposes a new design of a 2-qbit full adder (FA) as a basic unit to implement MVL ALU (AMLU) that has 8-units as pipeline, each one consists of 4-qbits to implement 32-qbit which is equivalent to 64-bit, without applying binary to quaternary conversion and vice versa. The proposed design increases microprocessors speed up to 1.65 times, but also a little increase of implementation.