A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respectively. Hall measurements confirmed that the films are n-type. The NO2 sensing characteristics of the SnO2:WO3 sensors were studied with various temperatures and NO2 gas concentrations. Both thin film and bulk sensors showed maximum sensitivity at temperature of 250 oC. Thin film sensors showed enhanced response in comparison to that of pellets.
This research aims to solve a problem in the field of accounting and financial knowledge in the world today, that is, the problem of creative accounting. Especially after the global financial crisis and the collapse of many large companies in the world, people find that they use creative accounting methods to distinguish them from reality, showing the results of their activities and their financial status. This research discusses the concept of creative accounting, the most important methods used in financial statements and its relationship with external auditing, and procedures to limit accounting creativity. This study uses descriptive analysis methods after confirming its theoretical aspects in practice. Using the statistical
... Show MoreIn this paper, the main work is to minimize a function of three cost criteria for scheduling n jobs on a single machine. We proposed algorithms to solve the single machine scheduling multiobjective problem. In this problem, we consider minimizing the total completion times, total tardiness and maximum tardiness criteria. First a branch and bound (BAB) algorithm is applied for the 1//∑Ci+∑Ti+Tmax problem. Second we compare two multiobjective algorithms one of them based on (BAB) algorithm to find the set of efficient (non dominated) solutions for the 1//(∑Ci ,∑Ti ,Tmax) problem. The computational results show that the algorithm based on (BAB) algorithm is better than the other one for generated the total number of
... Show MoreMedia plays an important role in shaping the mental image of their audiences for individuals, groups and organizations, States and peoples. It is the window through which overlooks the masses on events and issues, and in the light of their exposure to these means are their opinions and impressions.
Despite the importance of direct experiences in shaping opinions, drawing pictures and impressions, it is inevitable to rely on these means as individuals can not engage in direct experiences with thousands of events, issues and topics that concern their community and other societies.
There is no doubt that media is of great importance at the present time, because of its significant impact in the management of the course of pol
... Show MoreThe research discusses the issue of attribution to the verb, because the Arab scholars are unanimous in preventing attribution of the verb, because it is always informed of it, and does not inform about it, but this consensus violates the linguistic use. The research discusses this matter.
In view of the importance of the educational act, and the effective role played by the school in building the society on the basis of solidarity and equal opportunities, as well as the rehabilitation of emerging generations to exercise their rights and duties, as well as integration into the world of knowledge, communication and in different social and environmental circles[1]. The process of integrating special needs children, in regular or integrated classes within regular public schools or specialized rehabilitation educational centers, is of great importance to these groups of society, their families and society in general[2]. Based on the above, the research will start by answering the followingquestions:
How can the parents
... Show MoreStrives Total Productive Maintenance to increase the overall effectiveness of the equipment through the early involvement in the design and manufacture of equipment productivity. It also operates in an environment of simultaneous engineering work on the synchronization of activities to take advantage of early information by maintenance engineers, design, operation, and that helps to reduce the faults and facilitate future maintenance tasks.
Has adopted a search in the theoretical concept of the total maintenance productivity and concurrent engineering activities carried out during which the conjunction a
... Show MoreAtorvastatin have problem of very slightly aqueous solubility (0.1-1 mg/ml). Nano-suspension is used to enhance it’s of solubility and dissolution profile. The aim of this study is to formulate Atorvastatin as a nano-suspension to enhance its solubility due to increased surface area of exposed for dissolution medium, according to Noyes-Whitney equation.
Thirty one formulae were prepared to evaluate the effect of ; Type of polymer, polymer: drug ratio, speed of homogenization, temperature of preparation and inclusion of co-stabilizer in addition to the primary one; using solvent-anti-solvent precipitation method under high power of ultra-sonication.
... Show MorePseudomonas aeruginosa gram-negative, bacilli and facultative aerobic, P. aeruginosa cause cystic fibrosis patients, wounds, burns, and immunodeficienct patients, that have many virulence factors such as pyocyanin , cytotoxic ,biofilm formation and motility, Eighty-eight isolates belonging to P. aeruginosa were collected including the 66 clinical isolates obtained from different hospitals in Baghdad and were from different sources and 22 environmental isolates from previous studies of soil near oil fields. Microscopical and cultural characteristics were studied and diagnosed using biochemical tests, VITEC device, their ability to adhere to non-living (Polystyrene), living cell line (A549) and cytotoxicity of bacterial filtrate
... Show MorePM3 and DFT (6-311G/ B3LYP) level calculations were carried out for the 5Radialene molecule, which is exhibit D5h symmetry. The obtained equilibrium geometry was applied for the calculation of all 3N−6 vibration frequencies, and for the analysis of its normal coordinates and symmetry species, in addition to some physical properties such as heat of formation, total energy, dipole moment and energy difference of HOMO and LUMO levels (ΔELUMO-HOMO), using Gaussian-03 program. The so calculated frequencies according to DFT (6-311G/ B3LYP) fall in the ranges;
CH2 str. (3016-3098 cm-1), C=C str. (1662-1709cm-1), ring (C-C str.) (1268-1464 cm-1). δCH2 (890-1317cm-1), (δCCC) (562-631cm-1), γCH2 (738-946cm-1) and γring (γCCC) (
In this study, phosphorescence analysis (KPA) is used for determining soil collected from the Tigris River from Al- Karrada and Bab Al-Sharq in Baghdad and samples were taken from rainwater collected from Al-Rashad, Al-Obeidi, Al-Dora and Al-Sadr City in Baghdad. The measurements were carried out by the Iraqi Ministry of Health and Environment, in the Radiation Protection Center. The collection, removal and evaporation of the samples ranged from January to the end of March 2018. The results show the presents of concentration of 238U and 235U in soil samples and the rainwater samples. The conclusion of this work is the concentration of uranium in soil samples is more than recommendations by ICRP value of 1.9 μg /l. While all water sample
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