Background: Studying and investigating the transverse strength(Ts), impact strength(Is), hardness (Hr) and surface roughness(Ra) of conventional and modified autopolymerizing acrylic resin with different weight percentages of biopolymer kraftlignin, after curing in different water temperatures; 40°C and 80°C. Material and Methods: Standard acrylic specimens were fabricated according to ADA specification No.12 for transverse strength, ISO 179 was used for impact testing, Shore D for hardness and profilometerfor surface roughness. The material lignin first dispersed in the monomer, then the powder PMMA is immediately added. Ligninadded in different weight percentages. Then cured using pressure pot (Ivomet) in two temperatures;40°C and 80°C under 2 bar pressure, for 30 minutes.Atotal of 144samples were prepared for this study. Ts, Is, Ra, and Hr were tested, by using Instron universal testing machine, charpy impact tester, shore D tester, and profilometer respectively. Results: The transverse strength increased in both the conventional and modified onewhen compared with that cured in air. The addition of 0.5wt% lignin gave the higher effect (78.0017MPa) with highly significant difference found between groups at 40°C polymerizing temperature. While the impact strength in both temperatures in the modified resin revealed increased results than conventional one, 1.25wt% of kraft lignin gave the highest value (12.7355KJ/m2) with highly significant differences found between groups at 80°C polymerizing temperature. Hardness and surface roughness showed also highly significant differences found between groups at 40°C polymerizing temperature, all the groups had increased Hr. than the control one (78.95), while the Ra. decreased for 1.0% ,1.25,1.50 and 1.75 wt% lignin content to (0.26,0.10,0.063, 0.12µm) respectively in 40°C polymerizing temperature, the lowest value present in 1.75 wt% lignin (0.05 µm) at 80°Cpolymerizing temperature. Conclusions: It seems that increasing the polymerizing temperature to 40°C had a positive effect on the mechanical properties of autopolymerizing acrylic resin and the one enforced by kraft lignin biopolymer in low percentages. Increasing the polymerizing temperature to 80°C will doesn’t have much positive effect but it doesn’t deteriorate the mechanical properties. However, when submitted to increasing the temperature to 80°C, specimens showed a significant increase in impact strength.
Background: Globally, breast cancer is the second leading cause of death among women in Iraq. Several genetic and environmental factors are associated..
Background: Humeral diaphyseal fracture usually
heals with closed methods but when nonunion
develops then it needs surgical intervention in the
form of plating and bone grafting, intramedulary
nailing (open or closed simple or interlocking nails)
and external fixators (circular or one plane fixator).
In our unit we treated non union humeral
diaphyseal fracture with plating and bone grafting
shortening of fracture ends up to 4 to 5cm when
needed. Methods: This study was conducted at
Orthopaedic Department of AL-Sadar General
Hospital from January 2004 till December2005 .
We included 20 cases with atrophic non-union in
12(60%) and hypertrophic non-union in 8 (40%)
patients. All atrophic non-union w
In this work we experimentally investigated SWCNTs and MWCNTs to increase their thermal conductivity and electrically functionalization process using different reagents ((nitric acid, HNO3 followed by acid treatment with H2SO4), then washed with deionized water (DW) and then treated with H2O2 via ultrasonic technique. Then repeated the steps with MWCNTs and compare their results in an effort to improve experimental conditions that efficiently differentiate the surface of the single walled carbon nanotubes (SWCNTs) and multi walled carbon nanotubesi(MWCNTs) that less nanotubes destroy and to enhance the properties of them and also to reduce aggregation in liquid. the results were prove by XRD, and infrared spectroscopy (FTIR). The FTIR sp
... Show More
(3)
(3)
Polyetheretherketone (PEEK) has favorable biomechanical properties to be used as an implant material. Unfortunately, it is hydrophobic and does not promote cellular adhesion, which could result in poor integration with bone tissue. Bio-functionalization of PEEK surface with osteogenic peptides derived from bone extracellular matrix proteins is an exciting approach to encourage bone formation around the implant. In the current study, bone-forming peptide-2 was immobilized on PEEK surface using two different methods, using dopamine and a diglycidyl ether as conjugate compounds, respectively. Peptide quantification test revealed that the two strategies resulted in the most amount of peptides were attached with 0.5 mM concentration and no furth
... Show More
(3)
(5)
We manufactured the nanoparticles light emitting diode (NPs-LED) for organic and inorganic semiconductors to achieve electroluminescence (EL). The nanoparticles of Europium oxide(Eu2O3) were incorporated into the thin film layers of the organic compounds, poly(3,4,- ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT:PSS), N,N’–diphenyl-N,N’ –bis(3-methylphenyl)-1,1’-biphenyl 4,4’- diamine (poly TPD) and polymethyl methacrylate (PMMA), by the spin coating and with the help of the phase segregation method. The EL of NPs-LED, was study for the different bias voltages (20, 25, 30) V at the room temperature, from depending on the CIE 1931 color spaces and it was generated the white light at 20V, t
... Show More
(11)
Novel artificial neural network (ANN) model was constructed for calibration of a multivariate model for simultaneously quantitative analysis of the quaternary mixture composed of carbamazepine, carvedilol, diazepam, and furosemide. An eighty-four mixing formula where prepared and analyzed spectrophotometrically. Each analyte was formulated in six samples at different concentrations thus twentyfour samples for the four analytes were tested. A neural network of 10 hidden neurons was capable to fit data 100%. The suggested model can be applied for the quantitative chemical analysis for the proposed quaternary mixture.
The free zone or the free economy cities are cities with classification and functional specificity, although the history of the concept of these areas has been It dates back to distant eras, but the intellectual and philosophical construction with the support of intellectual approaches, the most important of which is globalization contributed to its rapid spread globally and taking a variety of forms and models. With the diversity of its formulas and objectives countries have competed in adopting the establishment of these areas, meanwhile The influence of related trends affected the contemporary formation of these sites. Therefore ,the research was directed focus on the importance of adopting a set of common indicators (collection
... Show MoreCapacitive–resistive humidity sensors based on polythiophene (P3HT) organic semiconductor as an active material hybrid with three types of metallic nanoparticles (NP) (Ag, Al, and Cu) were synthesized by pulsed laser ablation (PLA). The hybrid P3HT/metallic nanoparticles were deposited on indium-tin-oxide (ITO) substrate at room temperature. The surface morphology of theses samples was studied by using field emission scanning electron micrographs (FE-SEM), which indicated the formation of nanoparticles with grain size of about 50nm. The electrical characteristics of the sensors were examined as a function of the relative humidity levels. The sensors showed an increase in the capacitance with variation in the humidity level. Whil
... Show More
(9)
(6)