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
This in vitro study evaluated the influence of chemomechanical caries removal solution on the surface topography of metal-ceramic feldspar porcelain (MAJOR ceramic) and All-ceramic feldspar porcelain (Vita Alpha) using light polarizing microscope. Forty specimens of MAJOR ceramic and forty specimens of Vita Alpha ceramic of (12mm diameter & 3mm height) were prepared .All specimens were polished with silicon polishing burs, cleaned, autoglazed and stored in 37°C before exposure to Carisolv. Thirty specimens of each material randomly exposed to Carisolv gel for 5, 10 and 20 minutes respectively, other ten specimens were not, to act as control group. All specimens were subjected to surface roughness test by profilometer and evalua
... Show MoreNearly a century and a half has passed since Sarah Orne Jewett published her much anthologized short story “A White Heron” (1886), but commentators on the tale missed one of the most important points in the text. It is the story’s similarity to the traditional Euro-centric fairy tale of “Little Red Riding Hood”. As an author, writing at the end of the ninetieth century, a time that witnessed the demise of the Romantic movement in America and the beginning of the age of Realism, Jewett did not romanticize her characters, despite the idyllic landscape in which “A White Heron” is set. Her story can be analyzed as a text that aims at disseminating ecological awareness among her young readers. This study focuses on Jewett
... Show MoreThis study was aime to investigate the effect of addition different concentration of celery leaves to white soft cheese ,Treated cheese between 2018-2019, ,The finely Celery (Apium graveolens) leaves were adding to crude white cheese after texturizing in three leveles included (A,B,C) in addition of control antimicrobial activity of celery treated cheese against total account bacteria and coliform bacteria was estimated during (0, 5, 10, 15, 20) days. The results were shown that the higher concentration of celery in treated cheese, had a lower concentration of protein, lipid and ash content ( 16.81,15.13 and 4.30% respectively, but it had a higher moisture content 59.50%.also the total bacteria counts were decreasing significantly (0.05 P)w
... Show MoreDesert truffle is considered as a type of Syrian wild fungi that spreads heavily, and it occupies important rank in folk medicine, where its aqueous extract is used for the treatment of some eye and skin illnesses, and people prefer the use of black truffle. This work interested in studying of the most available species; Terfezia claveryi (black) and Tirmania pinoyi (white). The extracts of the two species of truffle were prepared by maceration with water, methanol, and ethanol 70%. Their total phenolic contents (TPC) and total flavonoid contents (TFC) were analyzed using Folin-ciocalteu and Aluminum chloride methods respectively, and their antioxidant activities was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and
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The ability of pulverized walnut-shell to remove oil from aqueous solutions has been studied. It involves two-phase process which consists of using walnut-shell as a filtering bed for the accumulation and adsorption of oil onto its surface. Up to 96% oil removal from synthetic wastewater samples was achieved while tests results showed that 75% of oil can be removed from the actual wastewater discharged from Al- Duara refinery in the south of Baghdad.
Complexes of 1-phenyl-3-(2(-5-(phenyl amino)-1,3,4- thiadiazole-2-yl)phenyl) thiourea have been prepared and characteized by elemental analysis, Ff-[R, and u.v./ visible spectra moreover, determination of metal content M%o by flame atomic absorption spectroscopy, molar conductance in DMSO solution and magnetic moments (peffl. The result showed that the ligand (L) was coordinated to Mn*2, Ni*2, Ct*2,2n*2,Cd*2, and Hg*2 ions through the nitrogen atoms and sulpher atoms. From the result obtained, rhe following general formula [MLClz] has been given for the prepared complexes with an octahedral geometry around the metal ions for all complexes. where M= Mn*2, Ni*2, cu*2, zn*z, cd*z, and Hg*2 l= l-phenyl-3-(2-(5-(phenyl amino)-1, 3,
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