Objectives. This study aimed at finding out whether anterior teeth angulation and inclination have a relationship with the maxillary teeth and dental arch dimensions. Methods. Fifty study models with normal occlusion were selected from the archive of the Department of Orthodontics at Baghdad Dental Faculty. Maxillary dental arch width and length at different points were determined in addition to measuring anterior teeth angulation, inclination, crown thickness, overjet, overbite, and Bolton’s ratios. The unpaired t-test and Pearson’s correlation coefficient test were used for data analysis. Results. No statistical gender differences were reported in all measurements except the dental arch widths and length where males had signif
... Show MoreThis study examines experimentally the performance of a horizontal triple concentric tube heat exchanger TCTHE made of copper metal using water as cooling fluid and oil-40 as hot fluid. Hot fluid enters the inner annular tube of the TCTHE in a direction at a temperature of 50, 60 and 70 oC and a flow rate of 20 l/hr. On the other hand, the cooling fluid enters the inner tube and the outer annular tube in the reverse direction (counter current flow) at a temperature of 25 oC and flow rates of 10, 15, 20, 25, 30 and 35 l/hr. The TCTHE is composed of three copper tubes with outer diameters of 34.925 mm, 22.25 mm, and 9.525 mm, and thicknesses of 1.27 mm, 1.143 mm, and 0.762 mm, respectively. TCTHE tube's length was 670
... Show MoreSolar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep
Background: Porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture or dettachment. This study examined whether different finishing lines and lingual shoulder preparations in the incisal area of the maxillary central incisor affect the bond of the porcelain veneers. Materials and methods: A two- dimensional finite element model was made. Location and magnitude of maximum Von Mises stresses were calculated in porcelain veneer. Six types of preparations were drawn as:incisal overlap of 0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth without shoulder preparation. Results: Stress formation is maximum in the incisal edge region. All the lingual shoulder
... Show MoreBackground: Lead-acid battery workers are at higher risk for systemic diseases as well as oral diseases like dental caries. The aim of this study was to assess selected salivary antioxidants and their relation with dental caries among lead acid battery factory workers in comparison with non-exposed group. Materials and methods: The sample consisted of 35 subjects aged 35-45 year-old who worked in Babylon lead acid battery factory in Baghdad city and matching group that not exposed to lead were selected as a control. Dental caries severity was recorded by using DMFS index, stimulated salivary samples were collected and analyzed for the measurement of salivary antioxidants (uric acid, total protein, catalase and glutathione peroxidase enzymes
... Show MoreKaolin ceramic compacts sintered at various temperatures are investigated to correlate their microstructure with their acoustic parameters. Pulse velocity , attenuation coefficient, and quality factor values are ducts from ultrasonic attenuation measurements, moreover, the dynamical mechanics parameters( Young and shear modules) exhibited an explicit relationship with the acoustic quality factor.inturn are related to the microstructure which is heavily affected by the sintering mechanism.
The importance of the research from a practical point of view lies in the fact that it presents a set of statistics and data that give a clear picture of how the Iraqi newspapers (the subject of the study) deal with the visit of "Pope Francis" to Iraq ، and what are the most prominent indicators and manifestations of that visit in promoting societal peace among the Iraqi public. From a scientific point of view، the research provides another scientific addition to the media library، especially with regard to journalistic treatments and methods of framing the Arab international press for the subject of the visit، which could be a starting point for other researchers to complete qualitative research in this field. The research prob
... Show MoreThe effect of three ionic liquids viz., 1-hexyl-3-methylimidazolium tetrafluoroborate (ILE), 1-hexyl-3-metylimidazolium hexafluorophosphate (ILF) and 1-octyl-3-methylimidazolium tetrafluoroborate (ILG) when used as surfactants on the performance of dissolved air floatation (DAF) was investigated.
Experiments were conducted at a temperature of 30-35 ºC, 10ppm ferric chloride as coagulant, 50% recycle ratio, pH 8, and 10 minutes treatment time to find oil and grease (OG) and turbidity removal efficiencies at saturation pressure (2-6) bar.
ILs were used at concentration of 50 µl/liter of treated water in two positions in DAF system; the saturation vessel and the treatment tank. The performance using ILs
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