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 layers of ITO/TPD: PMMA/CdSe/Alq3, ITO/TPD: PMMA/CdS/Alq3 and ITO/TPD: PMMA/ZnS/Alq3 devices which prepared by phase segregation method. The hybrid white light emitting devices consists, of three-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. The second layer was QDs while the third layer was tris (8-hydroxyquinoline) aluminium (Alq3). The results of the optical properties show that the prepared QDs were nanocrystalline with defects formation. The calculated of energy gaps from photoluminescence (PL) spectrometer were 2.38, 2.69 and 3.64 eV for CdSe, CdS and ZnS respectively. The generated white light has acceptable efficiency using confinement effect which makes the energy gap larger, so that the direction of the light sites are toward the center 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 ( 8-10.3 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 6250, 5310 and 5227K respectively. Fabrication of EL-devices from semiconductors material (CdSe, CdS and ZnS QDs) with hole injection organic polymer (TPD) and electron injection from organic molecules (Alq3) was effective in white light generation
In this work, an experimental study has been done to expect the heat characteristics and performance of the forced-convection from a heated horizontal rectangular fins array to air inside a rectangular cross-section duct. Three several configurations of rectangular fins array have been employed. One configuration without notches and perforations (solid) and two configurations with combination of rectangular-notches and circular-perforations for two various area removal percentages from fins namely 18% notches-9% perforations and 9% notches-18% perforations are utilized. The rectangular fins dimensions and fins number are kept constant. The fins array is heated electrically from the base
... Show MoreThe objective was to study the effect of prepared ginkgo biloba extracts against Candida albicans isolated from healthy persons. Conducting susceptibility test, biofilm formation test, phytochemical screening test, and antioxidant activity test. One hundred oral swabs sample were obtained from healthy persons with oral lesion attending dentistry teaching hospital in dentistry college, their age ranged from 1-30 years of both sexex. The studied samples collected through 8 months (April - December / 2018). This study included two different types of ginkgo bilola extracts were prepared as aqueous and ethanolic extracts. Many tests were used, which included isolation and identification of C.albicans, conduct susceptibility test, biofilm form
... Show MoreIn this research, the effect of adding two different types of reinforcing particles was investigated, which included: nano-zirconia (nano-ZrO2) particles and micro-lignin particles that were added with different volume fractions of 0.5%, 1%, 1.5% and 2% on the mechanical properties of polymer composite materials. They were prepared in this research, as a complete prosthesis and partial denture base materials was prepared, by using cold cure poly methyl methacrylate (PMMA) resin matrix. The composite specimens in this research consist of two groups according to the types of reinforced particles, were prepared by using casting methods, type (Hand Lay-Up) method. The first group consists of PMMA resin reinforced by (nano-ZrO
... Show MoreMicroalgae present much usefulness for antimicrobial research because of its enormous biodiversity and rapid growth rate. From this study results it is reaveled that Chlamydomonas reinhardtii were isolated from a pond of water in the province of Diwaniyah. The culture supernatants were obtained when extracted with methanol solvent. Antimicrobial activity of extracts was tested for pathogens, and the best inhibition zone obtained was against Candida albicans (32mm), S.aureus (15mm), and to E.coli (9mm). While it showed no effect against both S.epidermidis and Klebsiella spp. Biofilm was formed by all tested isolates with differences in its strength formation. The C. reinhardtii
... Show MoreAbstract The surface of kaolin was diagnosed by an AFM and the results were shown The height of the highest peak reached by a quantity of Kaolin surface is 2.5 µm, the granules, and their diameter with an average diameter of 666.1nm. Using Kaolin's adsorption properties, erythrosine was removed of its aqueous solution. It was determined that the maximal dye adsorption ranged 36.53–40.61%. The results of using the Freundlich, Langmuir, and Temkin adsorption isotherms revealed that at temperatures of (298,308,318) K, the Freundlich model was followed, the Langmuir model did not match, and the Temkin model could only be partially applied. There is also physical adsorption. One of the three kinetic models of the
... Show MoreIntroduction: The current study investigated the use of acid-treated rice husks to remove heavy metals and organic pollutants from water containing heavy metals (R2C and Cd2) and organic pollutants (phenol and atrazine). Methods: The adsorption effect of acid-treated rice husks was compared with other adsorbents such as activated carbon, chitosan, and bentonite clay. Result: both acid-treated rice husks and activated carbon were highly efficient materials, and thus, rice husks were established as a cost-effective alternative. It was revealed that acid treatment of rice husks enhanced adsorption capacity by half, and lead removal was nearly doubled. The most effective pH value for optimizing organic pollutants and heavy metals while
... Show MoreEvery so often, a confluence of novel technologies emerges that radically transforms every aspect of the industry, the global economy, and finally, the way we live. These sharp leaps of human ingenuity are known as industrial revolutions, and we are currently in the midst of the fourth such revolution, coined Industry 4.0 by the World Economic Forum. Building on their guideline set of technologies that encompass Industry 4.0, we present a full set of pillar technologies on which Industry 4.0 project portfolio management rests as well as the foundation technologies that support these pillars. A complete model of an Industry 4.0 factory which relies on these pillar technologies is presented. The full set of pillars encompasses cyberph
... Show MoreEndophytic fungi live inside plants or any part of them without creating any visible pathogenic signs. Endophytic fungi are found within medicinal plants and have shown strong biologic activity, such as anticancer and antioxidant activities, as well as producing extracellular enzymes. In this study, different fungal strains were isolated from the leaves of the medicinal plant Ziziphus spina, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Cladosporium sp., Rhizopus sp., and Mucor sp. Extracellular enzymes have been quantified using agar plate-based methods in which fungi were grown in specified growth media to detect the enzymes produced. The results showed that A. niger has the highest ability to produce amy
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