Fire is the most sever environmental condition affecting on concrete structures, thus investigating for fire safet, IJSR, Call for Papers, Online Journal
Background: asthma has an influence on craniofacial development. Recently evidences show that there is an association between oral health problems and chronic lung disease. The present study was designed to estimate the changes in arch dimension measurements among asthmatic children aged 12 years old who were collected from AL- Zahra Center Advisory for Allergy and Asthma and compare them with the non-asthmatic children of the same age and gender. Material and Methods: Fifty children (25 asthmatic and 25 non- asthmatic children) were included for the odontometric measurement. For both upper and lower study models, photographs were taken using special photographic apparatus for each child, and the statistical analysis were done by using SPSS
... Show MoreIn this research we study the effect of UV radiation on pure PC samples and doped samples with plasticizer (DOP) for different exposure times (6, 12, 18, 24h). The study have been made on the change in the IR spectra causes by the UV radiation on both kinds of samples, besides the morphology changes were also studied by the optical microscope. From the results we conclude that the increasing of exposure causes the elaboration of CO2 and C2 gases.
Background: Denture relining is the process of resurfacing of the tissue side of the ill fitting denture, the bond strength at the relining-denture base interface is most important for denture durability.The aim of present study was to evaluate the shear bond strength between the thermosens as relining material and different denture base materials that bonded by thermo fusing liquid. As this corrective procedureis the common chair side procedure in the dental clinic. Material and method: Sixty samples were prepared and divided into three main groups according to the type of denture base materials.Group (A) referred to the heat cure acrylic samples which consisted of 20 samples. Group (B) referred to the high impact acrylic samples which con
... Show MoreAim of the study: Using surface roughness and tensile bond strength tests, the objective of this investigation was to ascertain the impact of laser surface modification on the binding strength of injectable thermoplastic acrylic denture base material to acrylic-based soft-liner material. Materials and methods: Acrylic base soft liner material was bonded to injectable thermoplastic acrylic resin (Deflex). Forty specimens were created (20 disc, 20 dumbbells) 10 of each specimen type as control specimens, and 10 were treated with nano pulse Nd: YAG laser. The data were analyzed using the Kruskal-Wallis test and unpaired t-test (a=.05) and the roughness test was performed utilizing a double column universal test machine. Results: Compar
... Show MoreBackground: tooth debonding was one of the major reasons for denture repair. With the use of recently introduced thermoplastic denture base materials the problem of tooth debonding increased due to the nature of the bond between these materials and the acrylic teeth. This study was aimed to assess the bond of the acrylic teeth to conventional heat cure acrylic resin and to thermoplastic resin denture base material and methods to enhance it. Materials and methods: acrylic resin teeth were bonded to heat cure acrylic resin with and without wetting the ridge laps of the teeth with monomer and acrylic teeth with prefabricated retentive holes, unmodified and modified, in their ridge laps were processed with Valplast thermoplastic resin denture b
... Show MoreThis article presents the results of an experimental investigation of using carbon fiber–reinforced polymer sheets to enhance the behavior of reinforced concrete deep beams with large web openings in shear spans. A set of 18 specimens were fabricated and tested up to a failure to evaluate the structural performance in terms of cracking, deformation, and load-carrying capacity. All tested specimens were with 1500-mm length, 500-mm cross-sectional deep, and 150-mm wide. Parameters that studied were opening size, opening location, and the strengthening factor. Two deep beams were implemented as control specimens without opening and without strengthening. Eight deep beams were fabricated with openings but without strengthening, while
... Show MoreThis article presents the results of an experimental investigation of using carbon fiber–reinforced polymer sheets to enhance the behavior of reinforced concrete deep beams with large web openings in shear spans. A set of 18 specimens were fabricated and tested up to a failure to evaluate the structural performance in terms of cracking, deformation, and load-carrying capacity. All tested specimens were with 1500-mm length, 500-mm cross-sectional deep, and 150-mm wide. Parameters that studied were opening size, opening location, and the strengthening factor. Two deep beams were implemented as control specimens without opening and without strengthening. Eight deep beams were fabricated with openings but without strengthening, while
... Show MoreThe high temperature superconductor’s compounds are one of the hot spot field of science, due to their applications in industries. Hg0.8Sb0.2Ba2Ca2Cu3O8+δ and Hg0.8Sb0.2Ba2Ca1Cu2O6+δ, were manufactured using a doable-step of solid state reaction method. The samples were sintered at 800 ° C. The transition temperatures Tc are found from electrically resistively by using four probe techniques. The resistivity become zero when the transition temperature Tc(offset) have 131 and 119 K, and the onset temperature Tc(onset) have 139 K for Hg0.8Sb0.2Ba2Ca2Cu3O8+δ and 132 K for Hg0.8Sb0.2Ba2Ca1Cu2O6+δ. Analysis of X-ray diffraction showed a tetragonal structure with lattice parameters changes for all samples.
This paper demonstrates an experimental and numerical study aimed to compare the influence of openings of different configurations on the flexural behavior of prestressed concrete rafters. The experimental program consisted of testing six simply supported prestressed concrete rafters; 5 rafters are perforated, and the other one is solid as a reference. All rafters were tested under monotonic midpoint load. The variable which has been investigated in this work was the opening’s configuration (quadrilateral or circular) with the same upper and lower chords depths. The results indicate improvement in the beam flexural behavior using the circular openings compared to the quadrilateral o