Copper is a cheaper alternative to various noble metals with a range of potential applications in the field of nanoscience and nanotechnology. However, copper nanoparticles have major limitations, which include rapid oxidation on exposure to air. Therefore, alternative pathways have been developed to synthesize metal nanoparticles in the presence of polymers and surfactants as stabilizers, and to form coatings on the surface of nanoparticles. These surfactants and polymeric ligands are made from petrochemicals which are non- renewable. As fossil resources are limited, finding renewable and biodegradable alternative is promising.The study aimed at preparing, characterizing and evaluating the antibacterial properties of copper nanoparticles. Copper nanoparticles were prepared using gelatin biopolymer, CuSO4.5H2O ions and hydrazine as stabilizer, precursor salt and reducing agent respectively. However, vitamin C and NaOH solution were also employed as an antioxidant and pH adjuster. The synthesized copper nanoparticles were characterized using UV-visible spectroscopy (UV-vis), thermogravimetric analysis (TGA), zeta potential measurements powder, X-ray diffraction (XRD), field emission scanning electron microscope and transmission electron microscope (TEM). The UV-visible absorption spectrum confirms the formation of the CuNPs, which showed maximum absorbance at 583 nm. Results obtained from TEM indicated a decrease in size of particle from a low concentration to high concentration of the supporting materials. The optimum concentration of gelatin was found to be 0.75 wt%. The supporting materials used for this synthesis are biocompatible and the obtained products are stable in air. The synthesized CuNPs display promising antibacterial activities against B. subtilis (B29), S. aureus (S276), S. choleraesuis (ATCC 10708) and E. coli (E266) as gram positive and negative bacteria respectively.
The dielectric properties of epoxy/palm oil fiber composites at different concentrations 1,3,5, and 10% by weight, and frequency ranging from 100 Hz to 1000kHz.Epoxy, zinc oxide and oil palm empty fruit bunch (OPEFB)fiber composites were prepared by hand –lay up into sheets. The effects of incorporated fibers on the electrical conductivity and thermal conductivity of the composites were investigated. The electrical conductivity of the composites decreased with increasing OPEFB fiber content. Despite the slight decrease in conductivity, the composites still sufficiently conductive relatively to applications such as sensors after the fiber addition, the thermal conductivity increased to 0.41
Incremental forming is a flexible sheet metal forming process which is performed by utilizing simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. This work presents the single point incremental forming process for producing pyramid geometry and studies the effect of tool geometry, tool diameter, and spindle speed on the residual stresses. The residual stresses were measured by ORIONRKS 6000 test measuring instrument. This instrument was used with four angles of (0º,15º,30º, and 45º) and the average value of residual stresses was determined, the value of the residual stress in the original blanks was (10.626 MPa). The X-ray diffraction technology was used to measure the residual stresses
... Show MoreCustomers' creditworthiness standards are the key means employed by private commercial banks in assigning a suitable credit assessment for each customer. Accordingly, it had an instrumental role in indicating the degree of solvency of the potential customer before granting the required credit. The research problem reveals the nature of the relationship between the criteria of customer’s creditworthiness and banking liquidity. The most critical objectives of the study shed light on the role of using creditworthiness criteria as a tool for credit analysis of customers by banks that help reducing credit risks and thus increase banking liquidity. The questionnaire that was distributed to bank employees, the research sample, which w
... Show MoreIn this investigation, the mechanical properties and microstructure of Metal Matrix Composites (MMCs) of Al.6061 alloy reinforced by ceramic materials SiC and Al2O3 with different additive percentages 2.5, 5, 7.5, and 10 wt.% for the particle size of 53 µm are studied. Metal matrix composites were prepared by stir casting using vortex technique and then treated thermally by solution heat treatment at 530 0C for 1 hr. and followed by aging at 175 0C with different periods. Mechanical tests were done for the samples before and after heat treatment, such as impact test, hardness test, and tensile test. Also, the microstructure of the metal matrix composites was examine
... Show MoreObjective: In this study ,the effects of silver nanoparticles (Ag NPs)were investigated on the liver and kidney tissues. Methodology: The produced nanoparticles have an average particle size of about 30 nm. Eighteen male albino rats were used by dividing them into three groups, each group comprise 6 rats. First group(control group) given food and water like other groups by liberty. Second group was tail injected by (AgNPs) at dose of (0.4 mg/kg. body weight/day). Third group was injected by (AgNPs) at dose of (0.6 mg/kg. body weight/day) for 15 days. All animals were sacrified at the end of experiment. The liver and kidney tissues specimens were fixed in 10% formalin and histological preparations were carried out then stained with H&E. Path
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That Iraq's dependence on the revenues of the oil product in financing its development programs and growth rates , Making the economy affected by external forces represented by fluctuations in crude oil prices in the global market, Which is directly reflected on the performance and efficiency of the Iraqi economy.
The study adopted its objectives to analyze the time series for the period (1988 - 2015) through the use of standard and statistical methods, Four standard models were estimated to reach those targets, Where the results of the stability test showed instability of most variables at their original level, But to achieve stability when taking the first differences, While the result
... Show MoreThe problem of research is the need to find out the obstacles and difficulties facing women in accessing leadership positions at the University of Baghdad from their point of view. The importance of research comes from the importance of women in the university and their vital role in the development of society. The research objectives summarized the most important obstacles facing women Access to the leadership positions in the university and the relative weight of these obstacles as well as trying to identify differences in their view of these obstacles according to the variables of specialization (scientific, human) and the scientific title (Professor, Assistant Professor, Teacher, Assistant Lecturer). They were (144) university female
... Show MoreColloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate t
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