Lead-free 0.88(Na0.5Bi0.5)TiO3–0.084(K0.5Bi0.5)TiO3–0.036BaTiO3 (BNT–BKT–BT) piezoelectric ceramics were prepared using the conventional mixed-oxide method with a sintering temperature range of 1120–1200 °C. The effect of the sintering temperature on the crystal structure, microstructure, and densification, as well as the dielectrics, piezoelectrics, and the pyroelectric properties of BNT–BKT–BT ceramics were investigated. Scanning electron microscopy and X-ray diffraction were used to study the microstructures of the sintered samples. The results showed that the increase in sintering temperature was very effective in improving both the density and electrical properties. However, the samples deteriorated when the sintering temperature was above the optimum. The BNT–BKT–BT ceramics exhibited an excellent structure and electrical properties at a 1180 °C sintering temperature. The density of the ceramics reached a maximum value of 5880 kg/cm3, which is about 98% of the theoretical density. The ceramic exhibited a pyroelectric coefficient of (p) 366 μC/m2 K, a piezoelectric coefficient of d33 = 183 pC/N, a remanent polarisation of Pr = 38.43 μC/cm2, a dielectric constant of ε′ = 933, a loss tangent (tan δ) of 0.0235, and the figure-of-merit for detection was (FD) of 15.408 μPa1/2. Improvement in the pyroelectric properties is crucial for the development of infrared detectors and sensors.
Laboratory studies were conducted at the biological control unit, college of Agriculture, University of Baghdad to evaluate some biological aspects of the predator Chilocorus bipustulatus (Coleoptera: Coccinellidae), which is considered one of the most important predators on many insect pests, especially the scale insect, Parlatoria blanchardi, (Homoptera: Diaspididae) on date palms. The results showed that biological parameters of the predator were varied according to different degree of temperature. Egg incubation period was significantly different and reached to 7.5 and 5.44 day at 25 and 30°C respectively, Fertility was the same 100% at both temperature degrees. Larval growth periods were 17.41 and 16.12 day as well as the mortality
... Show MoreBackground: The purpose of this study was to assess the relation among the ramal length and width with various cervical and cranio-facial measurements for a sample of Iraqi adults with different skeletal classes. Materials and method: The sample composed of 71 Iraqi adults (36 females and 35 males) with an age ranged between 17-30 years and had different skeletal mal-relations using SNA, SNB and ANB to differentiate between them and assorting them into CL.I, CL.II and CL.III mal-relation. Each individual was subjected to clinical examination and digital true lateral cephalometric radiograph that had been analyzed using AutoCAD 2007 software computer program to determine sixteen linear and ten angular measurements. Descriptive statistics wer
... Show MoreThe study investigates the relationship between the volatility of the Iraqi Stock Exchange Index (ISX), and the volatility of global oil prices benchmarks, Brent and West Intermediate Texas (WTI), in additional to the Iraqi Oil, Basra Crude Light (BSL) which represents the most exported Iraqi oil and the major influential factor on the Iraqi governmental revenues. Using monthly data covering the period: 1/2005-12/1205, econometrical and technical tools represented by Co-incretion, Vector Error Correction Model – VECM, Granger Causality, and Bollinger band were employed in order to explore the relationship between the variables.
The econometric analysis revealed the impact of the oil prices volatility on
... Show MoreThe historical person study as a personality to the AL- Bazargan, one of the important
studies, is the shed light on the character had an effect of the political life in Iraq, an important
historical era involved many events, coincided with a national and historical by this personal
at the events successive positions that stage of the history of Iraq, especially if we know,
strongly his loyalty to the homeland and the earth, and intense hatred for any occupation or
colonization desecrate the land...
This was evident during his participation and his supervisor in 1920 liberal revolution
against the British occupation, and urged the need for adherence to the principles of
independence, and the emphasis on the nation
Intersectionality is a concept that focuses on social inequality towards black people and provides an analytical instruments for creating social justice issues in such a way in order to depict how social marginalization, or privilege occurs differently in various social positions. It does this by focusing on the interaction of multiple systems of oppression. Intersectionality is used to examines how the social factors; race, gender, and class can affect the people’s life especially the immigrants, black people, and refuges. This article will depicts how blacks in Canada are segregated and distinguished from white race. David Chariandy’s I’ve Been Meaning To Tell You: A Letter to My Daughter 2018 is analyzed through Kimberle Crenshaw
... Show MoreAim and Objectives: The objective of this study was to illustrate the link between periodontitis (PO) and endothelial dysfunction in hypertensive patients. Materials and Methods: This cross‑sectional study involved 53 hypertensive patients with or without PO compared with 28 healthy controls. On the basis of the study protocol, the participants were divided into three groups: Group (1): 24 patients with hypertension only, Group (2): 29 patients with hypertension and PO, and Group (3): 28 healthy controls. Lipid profile, endothelin‑1 (ET‑1), and high‑sensitivity C‑reactive protein (hs‑CRP) were measured. Blood pressure and body mass index (BMI) were evaluated. Diagnostic criteria of severe PO periodontal indices including plaque
... Show More The theory of the epic theater has received wide attention by filmmakers around the world because of its great impact on the artistic work of the theater and its relationship with societies, and among these directors the Iraqi directors have been influenced by the epic theater and its applications in the show.
In order to find out the effectiveness of these influences on the Iraqi director, I found the need to do this study, which was divided into an introduction and a theoretical framework that included two topics. The first topic (Philosophical References and the Intellectual Foundations of the Epic Theater Theory) deals with the philosophical foundations that crystallized the epic theory of Burch and the mechanism of working
The problem of the research lies in the bad timing of jump shot and layup due to lack of experience. The subjects were (5) youth basketball players under eighteen of the season 2015 – 2016. The results showed that agility didn't reinforce some fundamental offensive skills ending in jump shot and layup. The researcher recommended stressing offensive fundamental skills ending jump shot and layup without connecting it with agility. The training experience of most players participating in basketball league is very little thus more time should be offered to them before getting them into the league.
Coagulation is the most important process in drinking water treatment. Alum coagulant increases the aluminum residuals, which have been linked in many studies to Alzheimer's disease. Therefore, it is very important to use it with the very optimal dose. In this paper, four sets of experiments were done to determine the relationship between raw water characteristics: turbidity, pH, alkalinity, temperature, and optimum doses of alum [ .14 O] to form a mathematical equation that could replace the need for jar test experiments. The experiments were performed under different conditions and under different seasonal circumstances. The optimal dose in every set was determined, and used to build a gene expression model (GEP). The models were co
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