Preferred Language
Articles
/
alkej-90
Study the Dissociation Enthalpies for R134a Clathrate Hydrate in Binary and Ternary Systems
...Show More Authors

In the present work the clathrate hydrate dissociation enthalpies of refrigerant R134a+ water system, and R134a + water + salt system were determined. The heat of dissociation of three types of aqueous salts solutions of NaCl, KBr and NaF at three concentrations (0.09, 0.17and 0.26) mol·kg−1 for each salt type, were enthalpy measured. The Clapeyron equation was used tocalculate heat of dissociation of experimental data for binary and ternary system.In order to find the effect of compressibility factor on heat dissociation enthalpy, the study was conducted by using equation of state proposed by Peng and Robinson Stryjek-Vera (PRSV). The obtained results of dissociation enthalpy for binary system were (143.8) kJ.mol-1 without gas compressibility factor (z) and (136.08) kJ.mol-1 with z where the variation between two values was (5.3%). For ternary system (R134a+ water +NaCl) at three concentrations of this salt, the calculated values were in the range of (146.7 - 154.1) kJ.mol-1without z and (138.02-145.14) kJ.mol-1with z where the variation rang between two values was (5.8-5.7) %. The other two types of salts given similar results within (0.886 - 0.129) % deviation rang about NaCl results without z and (0.818-0.149) % deviation rang with z values.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Residual strength and strengthening capacity of reinforced concrete columns subjected to fire exposure by numerical analysis
...Show More Authors
Abstract<p>This study is a numerical investigation of the performance of reinforced concrete (RC) columns after fire exposure. This study aims to investigate the effect of introducing lateral ties and using the RC jacket on improving post-fire behavior of these columns, the effect of the duration of the fire on ultimate load of columns. The analysis was performed through ABAQUS, a 3D – non-linear finite element program. 4 m tall lengthening square RC column with a cross- section of 0.4 m × 0.4 m was used as a test specimen. The RC column was reinforced by 4Ø28 mm longitudinal bars bonded by steel tie bars of Ø10 mm spaced at 400 mm. The firing temperature was increased to 60</p> ... Show More
Scopus (6)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Mon May 01 2017
Journal Name
Journal Of The Mechanical Behavior Of Biomedical Materials
Bioactivity, cytocompatibility and thermal properties of experimental Bioglass-reinforced composites as potential root-canal filling materials
...Show More Authors

To evaluate the bioactivity and the cytocompatibility of experimental Bioglass-reinforced polyethylene-based root-canal filling materials. The thermal properties of the experimental materials were also evaluated using differential scanning calorimetry, while their radiopacity was assessed using a grey-scale value (GSV) aluminium step wedge and a phosphor plate digital system. Bioglass 45S5 (BAG), polyethylene and Strontium oxide (SrO) were used to create tailored composite fibres. The filler distribution within the composites was assessed using SEM, while their bioactivity was evaluated through infrared spectroscopy (FTIR) after storage in simulated body fluid (SBF). The radiopacity of the composite fibres and their thermal properties were

... Show More
View Publication Preview PDF
Crossref (30)
Crossref
Publication Date
Sat Apr 01 2023
Journal Name
Journal Of Engineering
Moisture Susceptibility of Hot Mix Asphalt Mixtures Modified by Nano Silica and Subjected to Aging Process
...Show More Authors

Moisture damage is described as a reduction in stiffness and strength durability in asphalt mixtures due to moisture. This study investigated the influence of adding nano silica (NS) to the Asphalt on the moisture susceptibility of hot-mix-asphalt (HMA) mixtures under different aging conditions. NS was mixed with asphalt binder at concentrations of 2%, 4%, and 6% by weight of the binder. To detect the microstructure changes of modified Asphalt and estimate the dispersion of NS within the Asphalt, the field emission scanning electron microscope (FE-SEM) was used. To examine the performance of Asphalt mixed with NS at different aging stages (short-term and long-term aging), asphalt mixture tests such as Marshall stability,

... Show More
View Publication Preview PDF
Crossref (11)
Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Annals Of Agricultural Sciences
Water use efficiency of potato (Solanum tuberosum L.) under different irrigation methods and potassium fertilizer rates
...Show More Authors

View Publication
Scopus (62)
Crossref (55)
Scopus Crossref
Publication Date
Thu Feb 12 2026
Journal Name
Journal Mustansiriyah Of Sports Science
Self-Efficacy and its Relationship to Psychological Adjustment among Table Tennis Players with Disabilities Special Needs
...Show More Authors

The introduction and importance of the research included that physical education and its various activities are important for the disabled. The exercise of physical activities by the disabled effectively contributes to raising their level of fitness and reducing diseases caused by lack of movement. Disabled people often suffer from psychological and social problems, and this feeling may be accompanied by a high level of anxiety, a lack of self-esteem and a loss of self-confidence. Psychological adaptation is one of the concepts of sports psychology interconnected with the psychological climate, as the process that the player seeks to meet his demands and needs. Adaptation includes the pursuit of emotional balance between the individual play

... Show More
View Publication
Publication Date
Wed Feb 01 2023
Journal Name
Journal Of The World Federation Of Orthodontists
Validity and reliability of three-dimensional modeling of orthodontic dental casts using smartphone-based photogrammetric technology
...Show More Authors

View Publication
Scopus (8)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Tue Sep 01 2015
Journal Name
Ama, Agricultural Mechanization In Asia, Africa And Latin America
Effect of three honeycomb interplant distances on yield and it components of two cultivars of bean
...Show More Authors

A factorial experiment (2× 3) in randomized complete block design (RCBD) with three replications was conducted to examine the effect of honeycomb selection method using three interplant distances on yield and its components of two cultivars of bean, Bronco and Strike. Interplant distances used were 75× 65 cm, 90× 78 cm, and 105× 91 cm (row× plant) represent short (high plant density), intermediate (intermediate plant density), and wide (low plant density) distance, respectively. Parameters used for selection were number of days from planting to the initiation of first flower, number of nodes formed prior to first flower, and number of main branches. Results showed significant superiority of the Bronco cultivar represented in the number

... Show More
Scopus
Publication Date
Tue Sep 01 2015
Journal Name
Journal Of Engineering
Reduction of Noise and Vibration of Spur Gear by Using Asymmetric Teeth Profiles with Tip Relief
...Show More Authors

Reduction of noise and vibration in spur gear experimentally by using asymmetric teeth profiles with tip relief was presented. Both of classical (symmetric) and asymmetric (with and without tip relief) spur gears are used in this work. Gear test rig was constructed to achieve torsional vibration measuring, and two modified cutters are designed and manufactured to achieve tooth profile modifications. First to cut asymmetric gear tooth with pressure angles (14.5o/25 o) without tip relief for loaded and unloaded tooth sides respectively, and second to cut asymmetric gear tooth with pressure angles (14.5o/25 o) for loaded and unloaded tooth sides respectively with tip relief to ach

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 07 2018
Journal Name
Applied Physics A
Effect of incorporation of conductive fillers on mechanical properties and thermal conductivity of epoxy resin composite
...Show More Authors

View Publication
Crossref (58)
Crossref
Publication Date
Sun May 01 2016
Journal Name
Journal Of Engineering
Field Observation of Soil Displacements Resulting Due Unsupported Excavation and Its Effects on Proposed Adjacent Piles
...Show More Authors

Soil movement resulting due unsupported excavation nearby axially loaded piles imposes significant structural troubles on geotechnical engineers especially for piles that are not designed to account for loss of lateral confinement. In this study the field excavation works of 7.0 m deep open tunnel was continuously followed up by the authors. The work is related to the project of developing the Army canal in the east of Baghdad city in Iraq. A number of selected points around the field excavation are installed on the ground surface at different horizontal distance. The elevation and coordinates of points are recorded during 23 days with excavation progress period. The field excavation process was numerically simulated by using the finite

... Show More
View Publication Preview PDF