Quantum dots of CdSe, CdS and ZnS QDs were prepared by chemical reaction and used to fabricate organic quantum dot hybrid junction device. QD-LEDs were fabricated using ITO/TPD: PMMA/CdSe/Al, ITO/TPD: PMMA/CdS/Al and ITO/TPD: PMMA/ZnS/Al QDs devices which synthesized by phase segregation method. The hybrid white light emitting devices consists, of two-layers deposited successively on the ITO glass substrate; the first layer was of N, N’-bis (3-methylphenyl)-N, N’-bis (phenyl) benzidine (TPD) polymer mixed with polymethyl methacrylate (PMMA) polymers in ratio 1:1, while the second layer was 0.5wt% from each type of the (CdSe, CdS and ZnS) QDs for each device.The optical properties of QDs were characterized by UV-Vis. and photoluminescence (PL) spectrometer. The results show that the prepared QDs were nanocrystalline with defects formation. The Eg calculated from PL were 2.38, 2.69 and 3.64 eV for CdSe, CdS and ZnS respectively. The generated white light properties with acceptable efficiency using confinement effect that makes the energy gap larger, thus the direction of the light sites are toward the centre of white light color.The hybrid junction devices (EL devices) were characterized by room temperature PL and electroluminescence (EL). Current-voltage (I–V) characteristics indicate that the output current is good compared to the few voltages ( 8-11.5 V) used which gives acceptable results to get a generation of white light. The EL spectrum reveals a broad emission band covering the range from 350 - 700 nm. The emissions causing this white luminescence were identified depending on the chromaticity coordinates (CIE 1931). The correlated color temperature (CCT) was found to be about 5500, 4885 and 3400K respectively. Fabrication of EL-devices from semiconductors material (CdSe, CdS and ZnS QDs) with hole injection organic polymer (TPD) was effective in white light generation. The recombination processes and I-V characteristics gives rises to the output current is good compared to the few voltages used which gives acceptable results to get a generation of white light.
The subject of this study is one of the most interactive media networks, which is the Instagram.The study uses a descriptive approach and focuses on how Instagram turns from a media tool to a marketing tool. The study problematic consists of this question: How Instagram turns to a marketing tool, and what are the advantages and the disadvantages for that?This study highlights the definition of Instagram, the creation of it and its improvement, the Instagram in Bahrain, the Instagram uses, the Instagram as a marketing tool, and the advantages and disadvantages of using Instagram for marketing.The study confirms that Instagram is a new media network, and focuses on how it develops on later stages and mentions the increase of the percentage
... Show MorePurpose: The purpose of the study is to compare and evaluate Earnings Management in Tunisia and Iraq. Theoretical framework: Earnings Management is an important topic that has been studied by a significant number of researchers, as well as those who are interested in the accounting profession. Earnings Management has gotten a lot of attention from academics, professionals, and other interested parties in recent years (e.g. Kliestik et al., 2020; Rahman et al., 2021; Gamra &Ellouze, 2021) Design/methodology/approach: The sample includes ten banks listed on the Bourse of Tunisia and Iraq Stock Exchanges for the year 2017. We have used a model of Kothari et al., (2005) as a tool to measure Earnings Management in both mark
... Show MoreFluconazole was used to test the susceptibility of Candida albicans isolated from different clinical samples, and to detect mutations in ERG11 gene, and their relationship to fluconazole resistance. Forty-eight isolates of Candida albicans were tested for susceptibility using the disc diffusion method (M-44). ERG11 genes of six isolates were amplified (four resistant, two susceptible) and sequenced. The sequenced genes were analyzed to detect the mutations. Out of 48 isolates of Candida albicans, 4 (8%) were resistant to fluconazole. Sixteen-point mutations were detected included 13 silent mutations, and three missense mutations. The mutations of A945C (E266D) and G1609A (V488I) were found only in susceptible Candida albicans isolates, whil
... Show MoreThis study is aimed to Green-synthesize and characterize Al NPs from Clove (Syzygium aromaticum
L.) buds plant extract and to investigate their effect on isolated and characterized Salmonella enterica growth.
S. aromaticum buds aqueous extract was prepared from local market clove, then mixed with Aluminum nitrate
Al(NO3)3. 9 H2O, 99.9% in ¼ ratio for green-synthesizing of Al NPs. Color change was a primary confirmation
of Al NPs biosynthesis. The biosynthesized nanoparticles were identified and characterized by AFM, SEM,
EDX and UV–Visible spectrophotometer. AFM data recorded 122nm particles size and the surface roughness
RMs) of the pure S. aromaticum buds aqueous extract recorded 17.5nm particles s
Background: Bacteriocin is a peptidic toxin has many advantages to bacteria in their ecological niche and has strong antibacterial activity. Objective: The aim of this study was to evaluation of bacteriocin using Streptococcus sanguinis isolated from human dental caries.
Subjects and Methods: Thirty five streptococcus isolates were diagnosed and tested for their production of bacteriocin, and then the optimal conditions for production of bacteriocin were determined. After that, the purification of bacteriocin was made partially by ammonium sulfate at 95% saturation levels, followed by and gel filtration chromatography
... Show MoreEffect of Chlorococcum humicola alcoholic algae extract was studied on the growth of, Pseudomonas aeruginosa, and Klebsiella pneumonia, which were isolated from contaminated water. The extract of Ch. humicola showed a high efficiency in reducing the numbers of the two types of bacteria. . The removal rate of K. pneumonia were 0.0, 48.4 and 57.0, The removal rate of P. aeruginosa were 63.1, 79.8 and 82.9% after24,48, 72 h respectively. The results improved that the K. pneumonia is more sensitive than P. aeruginosa for algae extract concentrations used in study ,and the beast effective time is 24h for the two bacterial species The aim of the study was to eliminate microorganisms using the Alcoholic algae extract. Especially P. aeruginosa and
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