Polyimide/MWCNTs nanocomposites have been fabricated by solution mixing process. In the present study, we have investigated electrical conductivity and dielectric properties of PI/MWCNT nanocomposites in frequency range of 1 kHz to 100 kHz at different MWCNTs concentrations from 0 wt.% to 15 wt.%. It has been observed that the electrical conductivity and dielectric constants are enhanced significantly by several orders of magnitude up to 15 wt.% of MWCNTs content. The electrical conductivity increases as the frequency is increased, which can be attributed to high dislocation density near the interface. The rapid increase in the dielectric constant at a high MWCNTs content can be explained by the formation of a percolative path of the conducting network through the sample for a concentration corresponding to the percolation threshold. The high dielectric constant at a low frequency (1 kHz) is thought to originate from the space charge polarization mechanism. I-V characteristics of these devices indicate a significant increase in current with an increase in multi-walled carbon nanotube concentration in the composites. The SEM images show improved dispersion of MWCNTs in the PI matrix; this is due to the strong interfacial interactions.
Edward Albee (1928-2016) is an American dramatist who is notorious for his controversial works. Albee's plays generate a crisis of a restraint situation and a point of no return where characters trespass the limits and get caught up in a tragic cycle. The Goat or Who is Sylvia? )2000) is one of his controversial pieces, addressing (human-animal relations). This theatrical masterpiece unleashes man's wildest desires and ravaging behavior. Bestiality is a criminal offense placed in the domain of mental disorders attributed to the lack of emotional support, anxiety, depression, and psychological problems. It is also a serious moral infraction of communities' socio-religious traditions. In this play, Martin’s bestiality lead
... Show MoreThe present study was designed to indicate the influence of the feeding plate on the nutritional and general health problems of the isolated cleft palate infants. For this study fourteen infants were taken, their ages between one day to one week, refered from cosmetic surgery and palate center to cleft lip and palate rehabilitation center in institute of technical medical / Baghdad for feeding plate purpose . Four infants put them as normal group; all those infants were subjected during (6th) month to evaluate the body weight, feeding problem and the respiratory infection. According to tables and figures this study showed a gradual improvement in nutritional problem including (feeding problem, body weight) and health problem (such as respir
... Show MoreNews feeds are at the forefront of news forms that are close to the public's attention for their rapid news content in two directions:
- its speed in summarizing events in one or two sentences easy to be understood and realized.
- highlight the most important contents of screenings or news broadcast.
The researchers felt that the importance of these brief news compared to news broadcast, breaking news and news subtitle are still ambiguous, as well as their contents.
The researchers selected the city of Baghdad as a community to research and prepare a questionnaire form containing (11) questions.
The questionnaires were distributed to a non-relative stratified
... Show MoreThis study presented an endeavour to integrate the value chain activities with the Balanced Scorecard for a comprehensive evaluation of an organization’s strategic performance. It also demonstrated the connection and the integration of the activities of the value chain with the Balanced Scorecard. The financial measurement was linked with non-financial measurement by integrating these techniques to achieve an appropriate performance that supports all aspects of the organizational performance. Consequently, the research problem in this study emerged, which is due to the concentration of many organizations on the measurement of financial performance. Notably, the latter caused the decline of some organizations from the competitive market. T
... Show MoreThis work has been done to prepare a series of new alkene compounds derived from 4-thiozolidinones by substituting different aldehydes, P-acetamido-phenol, and 2-mercapto-benzoimidazole, which were used as starting materials to form ester [I]a,b and then make hydrazides [II]a,b, which were used to prepare 1, 3, and 4-oxadiazoles [III]a,b, which were then used for prepared Schiff bases [IV]a-f, The next step was the synthesis of 4-thiazoldinone derivatives [V]a-f from Schiff bases. The final step was the synthesis of alkenes [VII]a-f, the prepared derivatives were identified with spectral methods (FT-IR, 1H-NMR, mass, and CHNS). The antibacterial activity of the prepared derivatives was evaluated against four types of bacteria, pos
... Show MoreBackground: Color stability of glass ionomers (GIs) could be affected by many factors such as pH and consumption of liquid medications like antibiotics. Most common antibiotics used during childhood are amoxicillin suspension (AM.S) and azithromycin suspension (AZ.S) which have acidic and basic pH respectively. Aim: to evaluate and compare the effect of AM.S and AZ.S on color stability of nano resin-modified GI. Methods: Thirty disc of nano resin-modified glass ionomer (2mm height x 4mm diameter) were divided into three groups (n=10 for each) and independently exposed to AM.S, AZ.S, and artificial saliva (A.S.). Color stability was evaluated in triplicate by VITA Easyshade® before and after three immersion protocols, repeated over
... Show MoreMany stone tools were found on a hill south of the Hor Al-Dalmaj which is located in the central part of the alluvial plain of Mesopotamia, between the Tigris and Euphrates Rivers. The types of rocks from which the studied stone tools were made are not found in the alluvial plain, because it consists of friable sand, silt, and clay. All existing sediments were precipitated in riverine environments such as point bar, over bank, and floodplain sediments. The collected stone tools were described with a magnifying glass (10 x) and a polarized microscope after they were thin sectioned. Microscopic analysis showed that these stone tools are made of sedimentary, volcanic igneous and metamorphic rocks, such as: sandstones, limestones, chert, con
... Show MoreTwo types of monofloral Malaysian honey (Gelam and Nenas) were analyzed to determine their antioxidant activities and total phenolic and flavonoid contents, with and without gamma irradiation. Our results showed that both types of honey can scavenge free radicals and exhibit high antioxidant-reducing power; however, Gelam honey exhibited higher antioxidant activity (p < 0.05) than Nenas honey, which is in good correlation (r = 0.9899) with its phenolic contents. Interestingly, we also noted that both irradiated honeys have higher antioxidant activities and total phenolic and flavonoid contents compared to nonirradiated honeys by Folin-Ciocalteu and UV-spectrophotometry methods, respectively. However, HPLC analysis for phenolic co
... Show MorePurpose: To evaluate the effect of different surface treatments on shear bond strength between dentin and IPS e.max lithium disilicate glass-ceramic. Materials and Methods: Eighteen extracted third molars were embeded in epoxy resin. The tooth was sectioned vertically in mesiodistal direction using a low speed hard tissue microtome. The buccal and lingual surfaces of each section were ground flat using 600 grit Silicone carbide paper. Eighteen ceramic discs consisted of lithium disilicate glass-ceramic were prepared with a diameter of 4.7mm and height of 2.2mm. The discs were divided in two groups (n=10): (1) IPS e.max treated with hydrofluoric acid and Monobond Plus (MBP) and (2) IPS e.max treated with Monobond Etch &Prime (MBEP). The toot
... Show MoreIn this research, the possibility of using waste wooden materials (reed and sawdust) was studied to produce sustainable and thermal insulation lightweight building units , which has economic and environmental advantages. This study is intended to produce light weight building units with low thermal conductivity, so it can be used as partitions to improve the thermal insulation in buildings. Waste wooden materials were used as a partial replacement of natural sand, in different percentages (10, 20, 30, and 40) % . The mix proportions were (1:2.5) (cement: fine aggregate) with w/c of 0.4. The values of 28 days oven dry density ranged between (2060-1693) kg/m3.The thermal conductivity decreased from (0.745 to 0.2
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