Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm−1(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.
The current study is a taxonomic account of three gastrotrich species that belong to Chaetonotidae (Phylum Gastrotricha) namely Ichthydium auritum Brunson, 1950 Lepidodermella squamata (Dujardin, 1841) and Chaetonotus anomalus Brunson, 1950. These species are registered as a new record from Iraq and were collected from several locations along the main outfall drain (MOD) in south of Baghdad, from January to December 2020. The species described in this article were found to be related to Hydrilla and Ceratophyllum and prefer environments rich in detritus and decomposing organic matter. The worms preferred water that is salty, hard, alkaline, and had good oxygen content.
The family Chalcididae (Order: Hymenoptera) is known as one of the large chalcidoid wasps with some distinct morphological characters. The first occurrence of two parasitoid species belonging to this family was reported in the Al-Husayniya district Karbala Province, Iraq; which are: Brachymeria podagrica (Fabricius, 1787) and Chalcis myrifex (Sulzer, 1776). Both species were collected by using the sweeping net from orchards during July 2020.
This research presents a study for precipitating phosphorus (as phosphate ion) from simulated wastewater (5ppm initial concentration of phosphorus) using calcium hydroxide Ca(OH)2 solution. The removal of phosphorus by Ca (OH)2 solution is expected to be very effective since the chemical reaction is of acid-base type but Ca(OH)2 forms complex compound with phosphate ions called. Hydroxyapatite Ca5 (PO4)3OH. hydroxyapatite is slightly soluble in water. This research was directed towards sustainable elements as phosphorus. Kinetics of the dissolution reaction of hydroxyapatite was investigated to find the best factors to recover phosphorus. The effect of con
... Show MoreThe sunflower plants are attacked by serious seed and soil-borne pathogens including charcoal rot disease that caused by
Morphological and molecular identification was done, using universal primers for molecular identification. Finally, a greenhouse experiment was conducted, and
The study focuses on identifying the reality of administrative creativity of secondary schools' managers in Al-zarqaa province. The descriptive approach was adopted to conduct this study. To achieve the study objective, the author designed a questionnaire composed of (24) items included (4) domains applied on (80) male and female school managers were selected randomly. The results showed that the administrative creativity level of secondary school's managers over all domains were too high which ranked as school management domain followed by public community domain then teacher domain and finally, school environment domain. Additionally, each of male, private sector, and experience over 10 years revealed significant differences.
Based on the systematic scientific investigation of artistic achievement, researchers (critics) adhere to mechanisms based on epistemology, through which it is envisaged to reveal the meaning of the achievement as the product of three actors: the effectiveness of an artistic sense, the effectiveness of an idea, and the arousal of taste according to systematic criticism procedures that investigate the new artistic achievement. Or, in a specific way, the possibility of meaning in all the accomplished from the aesthetics of artistic presentation and the character of the self-accomplished by the "artist" and the critic invokes his critical tools with certain cognitive foundations. In defining its nature from the rest of the other cultural ac
... Show MoreThe study of homomorphisms in cubic sets is considered one of the important concepts that transfer algebraic properties between different structures, so we study a homomorphism of a cubic set of a semigroup in a KU-algebra and defined the product of two cubic sets in this structure. Firstly, we define the image and the inverse image of a cubic set in a KU-semigroup and achieve some results in this notion. Secondly, the Cartesian product of cubic subsets in a KU-semigroup is discussed and some important characteristics are proved.
The wild populations of the vinegar fly Drosophila melanogaster Meigen from two regions in Baghdad , Saidiya and Tuwaitha were selected for this study to investigating the frequency of the dominant lethality , this parameter was investigated through fecundity and egg hatchability rate which considered as main indicator for the presence of mutation . The results showed that fecundity rate in Saidiya increased with time , so the lowest rate was 65.5 eggs per female in November and the highest was 87.4 eggs in May , the same results was observed for Tuwaitha except a significantly decrease in fecundity rate that was observed in May which was 42.7 eggs , as well as another significant differences between the two regions was observed in March
... Show MoreBackground: The PMMA polymer denture base materials are low mechanical properties, adaptation of the denture base to underlying tissue is important for retention and stability of denture. The aim of the study was toevaluate the effect of mixtureZrO2-Al2O3 nanoparticles on impact strength, transverse strength, hardness, roughness, denture base adaptation of heat cured acrylic resin denture base material. Materials and methods: One hundred (100) specimens were prepared, the specimens were divided into five groups (20 specimens to each) according to the test type, each group was subdivided in to two subgroups (control and experimental) each subgroup consist of 10 specimens, the experimental group included mixture of 2% (ZrO2-Al2O3ratio2:1) b
... Show MoreBackground: Change in palatal vault shape and Reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture. The aim of study is to evaluate the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on linear dimensional change and effect of palatal vault shapes on linear dimensional changes of non-reinforced and fiber reinforced high impact denture base acrylic resin Material and method: Three different palatal vault shapes were prepared on standard casts using CNC (computer numerical control) machine. 60 samples of heat polymerized high impact acrylic resin maxillary denture base were fabri
... Show More