In recent years, observed focus greatly on gold nanoparticles synthesis due to its unique properties and tremendous applicability. In most of these researches, the citrate reduction method has been adopted. The aim of this study was to prepare and optimize monodisperse ultrafine particles by addition of reducing agent to gold salt, as a result of seed mediated growth mechanism. In this research, gold nanoparticles suspension (G) was prepared by traditional standard Turkevich method and optimized by studying different variables such as reactants concentrations, preparation temperature and stirring rate on controlling size and uniformity of nanoparticles through preparing twenty formulas (G1-G20). Subsequently, the selected formula that prepared from the best tested condition was further optimized by preparing it using inverse method via the addition of gold salt to the reducing agent in opposite to the previous traditional method (G21). The optimized gold nanoparticles were characterized by SEM, EDX, TEM and zeta potential. The obtained results indicated that (G21) with reactants concentrations of 0.5mM and 10mM for HAuCl4.3H2O and trisodium citrate dihydrate respectively, 65°C of preparation temperature and 1500rpm of stirring rate was chosen as an optimized formula according to AFM provided gold nanoparticles with smoother surface, smaller size (average 8.75nm) with more uniform size distribution (7.32%) as well as short over all preparation time (27minutes). In addition to that all results of SEM, EDX and TEM indicated uniform spherical shape with zeta potential of -47.87. In conclusion, inversed method is promising for the preparation of gold nanoparticles with high monodispersity.
Theoretical and experimental investigations have been carried out on developing laminar
combined free and forced convection heat transfer in a vertical concentric annulus with uniformly
heated outer cylinder (constant heat flux) and adiabatic inner cylinder for both aiding and opposing
flows. The theoretical investigation involved a mathematical modeling and numerical solution for
two dimensional, symmetric, simultaneously developing laminar air flows was achieved. The
governing equations of motion (continuity, momentum and energy) are solved by using implicit
finite difference method and the Gauss elimination technique. The theoretical work covers heat flux
range from (200 to 1500) W/m2, Re range from 400 to 2000 an
The global globalization the world is experiencing has enabled international actors—states, international governmental and non-governmental organizations, such as liberation movements, international social movements, and even terrorist organizations—to use cyber power to achieve their goals. Therefore, this study discusses the impact of information power on the domestic environment of the United States.
This research discusses the verbal follow phenomenon in Al-Amali Abi Al-Qali’s book (seq.356 Hijri). It aims to limit the examples of this phenomenon in the book, and examine it phonologically. Accordingly, the researcher adopted the analaytical descriptive approach, taking into account Al-Rawi’s letter when ordering the verbal follow-based examples, and the order they took in the book in question. The purposes behind this phonological study of verbal follow in Al-Amali’s book are to: reach the sounds which Arabs prefer in the process of following, confirm different beautiful and desirable senses, have easy and speedy pronunciation, maintain harmony between adjacent sounds, count the sounds that occur at the beginning of the
... Show MoreAbstract---The aim of the current research is to identify the level of logical reasoning skills in chemistry students at the Faculty of Education for Pure Sciences/ Ibn Al-Haytham for the academic year (2021-2022). The differences in their level of skills according to the gender variable (males and females) and the academic stages (first- second - third - fourth). The descriptive approach was adopted because it corresponds to the nature of the research objectives. The research sample consisted of (400 )students selected in a relatively random stratified way. The researcher constructed a logical reasoning test, which includes (6) sub-skills , which is (proportional - probabilistic- synthetic- deductive- logic- variable adjustment). The psych
... Show MoreKE Sharquie, AA Noaimi, BAM Saleh, 2015
This paper set forth the spatial suitability of the informal settlement supposed to be distributed by the Iraqis government to poor people. The Iraqi government identified 9 locations of informal settlement in Baghdad city and acceptance it as a reality as a help for them to getting home. In this paper I discovered the suitability of those locations which one will be suitable more than others for living. The analysis process was applied using the GIS environment – spatial analysis. According to the results, It has been identified as the most important measures to identify which one of these areas suitable for development for housing by using some criteria (Distance from the city center, Proximity from transport routes, Proximity of high v
... Show MoreThe present paper focuses on examining the style of both the civilized dialogue of Prophet Hud (PBUH) in the Glorious Qur'an, and the debated dialogue of Aad’s people. The study consists of an introduction which shows the importance of the civilized dialogue and its significant impact on containing, accepting, and persuading the other in peaceful ways without intolerance and violence. Then, the conditions and techniques of the civilized dialogue and its types have been mentioned. This is followed by the practical side of the study, which involves examining stylistically the techniques used in Hud’s (PBUH) civilized dialogue to be invested later in people’s future conversations. It is also concerned with investigating stylistically
... Show MoreIn this study, from a total of 856 mastitis cases in lactating ewes, only 34 Streptococcus agalactiae isolates showed various types of resistance to three types of antibiotics (Penicillin, Erythromycin and Tetracycline). St. agalactiae isolates were identified according to the standard methods, including a new suggested technique called specific Chromogenic agar. It was found that antibiotic bacterial resistance was clearly identified by using MIC-microplate assay (dilution method). Also, by real-time PCR technique, it was determined that there were three antibiotics genes resistance ( pbp2b, tetO and mefA ). The high percentage of isolate carried of a single gene which was the Tetracycline (20.59%) followed by percentage Penicillin was
... Show MoreThis research paper which is entitled “Analysis of Verbs Forms in Sa’eed Faeeq’s Short Story: Cloud in the Sky” deals with the forms of verbs (i.e., kinds of tenses and suffix analysis). It is one of the applied studies. Verbs are basic elements in Turkish sentences. Their function is to state the predicate which is a sentential essential part. Verbs denote sentence construction, action and formal aspects. Forms are added to the base of verbs in the Turkish language giving the verbs their final structures. Such structures are set in a distinct planned way. The verbs used in the Turkish language which are distinguished by one of these forms are known as simple tense verbs.
Sait Faik'in ( "Havada Bulut" adlı Hikayesinde Fi
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