Online ISSN: 2788-6867

Main Subjects : Materials Science

A Physico-chemical Contribution to the Conventional Technique of Preparation Graphene Oxide

Zainab B. Abd; Nasser A. Habib; Abbas khammas

Journal of Applied Sciences and Nanotechnology, 2022, Volume 2, Issue 2, Pages 70-78
DOI: 10.53293/jasn.2021.4296.1090

The modified Graphene Oxide (GO) synthesis methods used over the past sixty years is contributed mainly to improving its characteristics and increasing its advanced applications. Therefore, in this work, modifying Hummer’s Method via oxidizing graphite flakes using one type of acid (H2SO4) was performed without any chemical agents. Also, ultra-sonication and filtration were implemented with optimal parameters (50 kHz frequency during 120 minutes at room temperature 30 oC) to prepare GO nanosheets. These procedures improved GO characteristics via analyzing; Particle size, X-ray diffraction pattern (XRD), Ultra-violet visible (UV-vis) absorption, and Scanning Electron Microscopy (SEM). The obtained results showed that the characteristics of GO nano-sheets had met the preparation requirements, such as reducing the average diameter of GO nano‑sheets from 313 nm to 94 nm. Moreover, characterizing the diffraction angle of GO at 9.86o and the optimal absorption by UV-vis achieved at 230 nm. The synthesis and exfoliation of GO nano-sheets were carried out with fewer impacts of toxicity using distilled water. Finally, this GO synthesis in the lab might be used to make a variety of nanocomposites.

A Short Review on Preparation and Characterization of Iraqi Porcelanite Aggregate Concrete

Sahar I. Ahmed; Aqeel S. Al-Adili; Awham M. Hameed

Journal of Applied Sciences and Nanotechnology, 2022, Volume 2, Issue 1, Pages 49-58
DOI: 10.53293/jasn.2021.3565.1028

Conventional concrete is recognized for its high density, which leads to a higher cost of building foundations and columns. Recently, many efforts have been made to produce lower density concrete with acceptable and applicable mechanical properties. One option can reduce the density of the conventional concrete by using partial or total replacement of porcelanite instead of natural gravel.  Porcelanite aggregate concrete can be prepared by adding different ratios of porcelanite and several other additives to the mortar, depending on the required density of the prepared porcelanite concrete. This study aims to assess porcelanite aggregate concrete components, manufacturing methods, and features of porcelanite aggregate concrete. Furthermore, this literature review aims to appraise and provide a complete vision of the testing program, including compressive strength, density, porosity, splitting tensile strength, and water absorption of porcelanite aggregate concrete. Also, this paper focuses on studying the development and applications of the porcelanite aggregate concrete, which will be presented in detail through this study.

Study of the Mechanical and Thermal Properties of Refractory Mortars from Kaolin and Bentonite

Faten Hasan Gata; ENAS MHUI

Journal of Applied Sciences and Nanotechnology, 2022, Volume 2, Issue 1, Pages 69-79
DOI: 10.53293/jasn.2021.3743.1039

In this paper, Mortar was prepared from medium alumina refractory grog, bricks crashed as a mean material to a particular size, and Iraqi raw (kaolin or bentonite) as binding materials. Refractory bricks were crushed, milled, then sieved to three particle sizes: fine as (1.18 >fine> 0) mm, medium as (2.36 > medium > 1.18) mm, crushed as (400 > coarse > 2.36) mm. Then these particle sizes were mixed with Iraqi raw kaolin or bentonite with selected ratios (10,15,20,30 and 40) %. Specimens were formed by the wetting method, then drying it at laboratory temperature for one day, followed by firing it at 1200 ℃. Results showed that the porosity of specimens decreases when increasing the clay ratio from 3-4% (kaolin or bentonite), and the bond strength between grog and clay increases when increasing the clay ratio from 2-3% (kaolin or bentonite). Also, the diametrical strength increases when increasing the clay ratio from 4-7% (kaolin or bentonite). The thermal shock results showed that K-mortar is better than B-mortar, depending on the results we obtained through the effect of temperature and diametrical strength. The SEM results showed that mortar structure was produced by adding 40% bentonite with small irregularly shaped. The mortar was produced by adding 40% of kaolin which possesses regular mullite crystals. Finally, the results of the test EDS that K-mortar were revealed in showed that there is no adsorption of carbon while B-mortar showed that there is adsorption of carbon atoms.

Sequencing Analysis of cvaC Gene in Acinetobacter Baumannii That Isolates from Different Infections

Rana M. Abdullah; Rasha Z. T. Ahmed

Journal of Applied Sciences and Nanotechnology, 2021, Volume 1, Issue 4, Pages 24-31
DOI: 10.53293/jasn.2021.3782.1042

Acinetobacter baumannii is one of the opportunistic nurses responsible for many acquired infections in hospitals due to its ability to resist many antibiotics. This is one of the problems facing hospitals in the world. Identification of the cvaC gene and sequence analysis in Acinetobacter baumannii isolates from various infections, and mutation detection in this gene. From 1st of September to 30th of November, 2016, 200 Acinetobacter baumannii isolates were obtained from various clinical samples. Follow fifty isolates from blood, twenty isolates from urinary tract infections, thirty isolates from wound infections, forty isolates from burn infections and twenty-five isolates from stool samples from various hospitals (Central Children's Hospital, Al Karama Hospital, Karkh General Hospital, Al-Ameen Medical City Hospital, Educational Labs, Baghdad Teaching Hospital, Child Protection Hospital, Burns and Wounds Hospital) in Baghdad city. Identification forty isolates confirmed that they belong to Acinetobacter baumannii, including fourteen isolates from a stool sample, nine isolates from blood, eight isolates from burns, four isolates from wound infections, and Respiratory tract infection, , and only one isolate from urinary tract infections sample. Genotypic detection of the cvaC gene of Acinetobacter baumannii showed the presence of this gene in 16 isolates (40%) and Sequencing analysis of cvaC has shown seven genetic mutations and only one mutation has been converted amino acid Alanine to Valine.The amino acid Alanine was changed to Valine in Position 656 at Subject 678, resulting in silent mutations that did not affect protein translation and other mutations that resulted in a change in the amino acid arrangement and protein translation.

Preparation of Micro Barium Titanate Powder and Comparison with Nano Powder Properties

Ghadeer Sadiq Jassim; Mojahid Najim; Wafaa Salih

Journal of Applied Sciences and Nanotechnology, 2021, Volume 1, Issue 4, Pages 12-23
DOI: 10.53293/jasn.2021.3653.1033

In this paper, a homogenous pure Barium Titanate with formula (BaTiO3) was prepared from pure Barium Carbonate (BaCO3) and titanium dioxide (TiO2) using the solid-state reaction technique, were used as raw materials having micro size by mixing of molar ratio [1:1], the powder was calcined at temperatures (900-1350) °C. The solid-State reaction can consider as an attractive process realistic alternative to the expensive wet-chemical route, according to X-ray diffraction, all of the peaks of Barium Titanate powder were perfectly suited to the positions of the peaks of the standard tetragonal phase in the pattern for this process. And with preferred crystalline size for the powder calcined at 1350 °C manifested the best results, where all the peaks indicate the formation of Barium Titanate completely. In addition, each BaTiO3 Nanopowder was compared to a micro powder that had been manufactured, by conducting x-ray diffraction, diffraction peaks undergo shifting toward higher angle to the high value of 2Ө, and Nano powder particles are smaller than micro powder particles. And this refers to a decrease in lattice parameters, in terms of the peaks of the Nano powder preceding the peaks of the micro powder of BaTiO3 and that match the result that is obtained by scanning electron microscopy (SEM).

Synthesis and Physical Characterization of PMMA/PP and PMMA/ PAN Composites for Denture Applications

Hassan Adnan Sharhan; Zaynab Naif Rasheed; Jawad Kadhim Oleiwi

Journal of Applied Sciences and Nanotechnology, 2021, Volume 1, Issue 3, Pages 13-23
DOI: 10.53293/jasn.2021.3759.1040

This study involves on manufacture of denture base resin with advanced physical properties through the addition of two type of synthetic fibers used as reinforcing materials polypropylene (PP) and Poly acrylonitrile (PAN). In this research, groups of three samples of both PMMA/PP and PMMA/PAN composites were prepared with the selected fiber weight ratios of 1.5, 3.5, 5.5 and 7.5 %Wt. Physical properties such as water absorption, thermal conductivity and density were evaluated under normal conditions. The chemical bond structure was also investigated for all samples using FTIR test. The results showed that when fibers ratio increased until 7.5 %Wt., the water absorption increases, as well for each fiber which was over 0.6% compared to the 0.3% of the neat sample. A noticeable decrease in the thermal conductivity property from 0.33 W/m.K for PMMA/PP and 0.24 W/m.K for PMMA/PAN comparing to 0.46 W/m. K of the neat polymer was revealed. As for the density results, it was found that when the fibers ratios were increased, the sample density slightly decreased and reached 1.09 g/cm3 for PMMA/PP and 1.1 g/cm3 for PMMA/PAN at the maximum fibers rate. FTIR results indicated there was no new peaks appeared after reinforcement with both fibers. This could refer to the good physical bond between the mixtures, no new material formed.

Homogeneity of Lithium Metasilicate-Copper Oxide Glass-Ceramics by Weibull Modulus

Duraid Mahdi; Shihab Zaidan; Muthafar Al-Hilli

Journal of Applied Sciences and Nanotechnology, 2021, Volume 1, Issue 2, Pages 27-36
DOI: 10.53293/jasn.2021.3534.1027

The work idea is finding out how the homogeneity of dielectric strength property in lithium metasilicate glass-ceramic with addition weight percentage increasing of CuO. It prepared four specimens, one without CuO addition lithium metasilicate glass-ceramic LSGC and consists of Li2O-SiO2 binary system glass batch with weight percentages 45 wt% Li2O and 55 wt% SiO2. It added to the binary system CuO with different weight percentages to prepare the rest three specimens in front of the Li2O weight percentage decreasing as 1 wt% LC1S, 2 wt% LC2S, and 3 wt% LC3S. The glass batches for four specimens were mixed and used melting-quenching method at temperature of 1195OC for soaking time 2 hrs. It used platinum crucible (90 Pt-10 Rh) and immediately cooled in the cold water of temperature at 3OC. This process was repeated twice for all specimens and the produced frit was milled by agate mortar. Addition of P2O5 and TiO2 as nucleating agents with weight percentage 3 wt% P2O5 and 1 wt% TiO2 and prepared compact discs with dimensions 18 diameter × 2.58 thickness mm by the used biaxial hydraulic press with 5 ton for 30 s under pressure. The heat treatment was done for all glass batch compact discs of temperature at 950OC for 6 hrs as soaking time and breakdown voltage test was done executed 10 different spots in each specimen and Weibull modulus was used to know the homogeneity of dielectric strength property and coincided with Field Emission Scanning Electron Microscopes (FE-SEM) images. It got a good match between Weibull modulus results and FESEM images which indicating that Weibull modulus is the active tool that can be used for knowing the homogeneity of any property. The high average dielectric strength is 9.116 kV/mm for LC1S while the lower average dielectric strength is 7.101 kV/mm for LSGC and this back to more homogeneity and fewer defects in LC1S than LSGC.

Evaluation of Hot Corrosion Properties for Nano-coated Superalloy

abbas khammas; Thear Tarish; Abdul Raidha; Ali Khudair

Journal of Applied Sciences and Nanotechnology, 2021, Volume 1, Issue 1, Pages 7-14
DOI: 10.53293/jasn.2021.11208

The purpose of this study is to optimize the hot corroded pack coated Ni-based super alloy K417G using composite desirability. Pack cementation parameters optimization was performed using quality characteristics of diffusion coatings for pack cementation process, i.e. salt activator, Nano-powders master alloy powder and wt.% Ge. Analysis of variance (ANOVA) was used for observing the most influencing pack cementation parameters on the quality characteristics, i.e. Na2So4-6% wt. V2O5 (kp1), 100 wt% NaSO4 (kp2), and 75 wt. % NaSO4-25 wt % NaCl (kp3). A confirmation test was performed after the optimal process parameters were determined using composite desirability analysis. Based on analysis of variance results, the wt.% of Geis the most significant controllable diffusion coating factor for the hot corroded pack coated K417G at optimum setting conditions (A2, B1, C3) i.e. activator (NaCl), master alloy (90Cr-10Al) and wt.% of Ge (2%) according to the quality characteristics. Composite desirability was successfully applied on optimization of hot corroded pack coated K417G using multi-performance characteristics.