Preferred Language
Articles
/
alkej-293
Thermal Behaviour of Paraffin Wax/Poly Vinyl Alcohol Composite Material
...Show More Authors

Polymer additives binder system provides many properties useful in thermal energy storage (TES) then developed the efficient energy storage materials and green strength bodies system.

This paper studies the thermal energy storage property for polyvinyl alcohol (PVOH) / paraffin wax (WPw) blends. To enhance paraffin wax thermal conductivity, PVOH as a material which high conductivity was employed. A fixed weight of Paraffin wax was dispersed with PVOH heterogeneously at different additive weights ratios of PVOH/Pw (50/50, 67/33, 75/25, and 80/20) wt. ratio respectively. The composite material was prepared using wetted pressing method.

Both base materials (polyvinyl alcohol and paraffin wax) were scanned using differential scanning calorimeter (DSC) under non-isothermal conditions, the result was analysed to determine the thermal transition temperature of PVOH and paraffin wax base material. The thermal decomposition of PVOH and waste paraffin wax proved that high transition temperature (TG) for PVOH reached 209ᴼc rather than wax of 60ᴼc respectively. This result shows that PVOH suppress the thermal stability of PVOH/waste paraffin wax composites. Afterward examines the thermal conductivity enhancement using Lee- disk techniques. Composite materials PVOH/paraffin wax have a high thermal conductivity which increases thermal conductivity of waste paraffin wax as a heat storage media and  this allows to apply change in phase with wide range of temperatures, and the highest decreased ratio of phase-change heat is very low, compared to that of paraffin only. Therefore, PVOH, added to paraffin which has significant potential for enhancing the thermal storage characteristics of paraffin.

A wax/PVOH system acts as strength body resistance to sever contact of both air and moisture then a moisture absorbance percent was achieved by use both Fourier transform infrared spectroscopy (FTIR) techniques and moisture solutions (100% H2O) for all pure and composite material system Pw/PVOH, the results shows high resistance to ambient conditions (air/ moisture) for composite system rather than pure materials (PVOH and Pw). 

                                              

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Nov 05 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effect of Addition Retention Bead and Repair Material on Transverse Strength of Repaired Acrylic Denture Resin
...Show More Authors

Objective: One of the most important practical deficiencies of present denture base materials is fracture, therefore many
attempts have been made to reinforce of the repaired denture base resin. A desirable objective for this service is to obtain
optimum strength for repairs, which can be achieved by making available a good bond between original and repaired
materials.
Methodology: The present study was carried out to evaluate and compare the transverse strength of acrylic specimens
repaired by two different materials (hot-cure and cold-cure acrylic resin). A total of 50 specimens were prepared by hot
(40) repair: (10) by hot with retention bead, (10) by cold with retention bead and (10) repair by hot only, (10) repair

... Show More
View Publication Preview PDF
Publication Date
Fri Sep 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Thermal and Catalytic Degradation Kinetics of High-Density Polyethylene Over NaX Nano-Zeolite
...Show More Authors

Thermal and catalytic pyrolysis of waste plastics in an inert atmosphere has been regarded as a creative method, since pyrolysis can convert plastics waste into hydrocarbons that can be used either as fuels or as a source of chemicals.

Natural Iraqi kaolin clay was used to synthesis the NaX nano- zeolite by hydrothermal conditions with average particle size equal to 77.63nm.Thermal decomposition kinetics of high-density polyethylene (HDPE) in the absence and presence of catalysts nano NaX Zeolite was investigated. Thermal and catalytic degradation of HDPE was performed using a thermogravimetric analyzer in nitrogen atmosphere under non-isothermal conditions 4, 7 and 10 °C/min heating rates were employed in thermogravimetric anal

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Augmentation of Nanofluids Heat transfer in a Circular Tube with Baffled Winged Twisted Swirl Generator
...Show More Authors

This article introduces a numerical study on heat exchange and corrosion coefficients of Zinc–water nanofluid stream in a circular tube fitted with swirl generator utilizing CFD emulation. Different  forms of swirl generator which have the following properties of plain twisted tape (PTT) and baffle wings twisted tape (BTT) embeds with various ratio of twisting (y = 2.93, 3.91 and 4.89), baffle inclination angles (β = 0°, - 30° and 30) joined with 1%, 1.5% and 2% volume fraction of ZnO nanofluid were utilized for simulation. The results demonstrated that the heat and friction coefficients conducted by these two forms of vortex generator raised with Reynolds number, twist ratio and baffle inclination angles decreases. Likewise, t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
الاحتیاجات التدریبیة لمعلمي ومدرسي مادة التربیة الاسلامیة: الاحتیاجات التدریبیة لمعلمي ومدرسي مادة التربیة الاسلامیة
...Show More Authors

Abstract
The teacher I the heart of the educational process and the basic mover of
the educational interaction. The good training and preparing of the teacher
refines his abilities and makes him ready for the developing and evaluating his
work continuously. due to the importance of the teacher's training according to
the recent developments in his domain, the ministry establishes the training
institutions and sessions everywhere in order to develop the level of teaching
of the educational programs designed for the subject of the Islamic education
and its various activates, and to apply the best techniques that can raise the
level of performance in training and preparing the teachers of the Islamic
education<

... Show More
View Publication Preview PDF
Publication Date
Thu Sep 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Determination of Surface Roughness and Accuracy of Alginate Impression Material Disinfected by Immersion
...Show More Authors

Background: This study was conducted to evaluate the surface roughness and dimensional accuracy of commercially obtainable alginate impression material in terms of imbibition after immersion in two different media. Materials and method: Two disinfecting agents, ethanol 70% and povidone-iodine 4%, were used to access the dimensional accuracy and surface roughness of alginate impression material. Weights of specimen discs of alginate impressions were measured before and immediately after immersion to gain a measure of imbibition. For surface roughness, disinfected specimens rectangle was examined before and after disinfection. Results: Minimal changes in weight were observed after disinfection, but a statistically non-significant differenc

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Aip Conference Proceedings
Study optoelectronic properties for polymer composite thick film
...Show More Authors

View Publication
Scopus (9)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Wed Oct 10 2018
Journal Name
Steel And Composite Structures
Removable shear connector for steel-concrete composite bridges
...Show More Authors

The conception and experimental assessment of a removable friction-based shear connector (FBSC) for precast steel-concrete composite bridges is presented. The FBSC uses pre-tensioned high-strength steel bolts that pass through countersunk holes drilled on the top flange of the steel beam. Pre-tensioning of the bolts provides the FBSC with significant frictional resistance that essentially prevents relative slip displacement of the concrete slab with respect to the steel beam under service loading. The countersunk holes are grouted to prevent sudden slip of the FBSC when friction resistance is exceeded. Moreover, the FBSC promotes accelerated bridge construction by fully exploiting prefabrication, does not raise issues relevant to precast co

... Show More
View Publication
Scopus (52)
Scopus Clarivate
Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
Effect of sulfuric acid solution on thermal conductivity and impact strength of epoxy resin reinforced by silicon dioxide powder
...Show More Authors

In this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared by hand Lay-up method, to measure the change in the thermal conductivity and Impact Strength of epoxy resin before and after immersion in H2SO4 Solution with a 0.3N for 10 days. The results before immersion decreases with the increase of the weight ratios of the reinforcement material (SiO2), It changed from (82.6×10-2 to 38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) % respectively, but after immersion time in the chemical solution where it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became (46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of the Impact strength decreased by increasing the percentage weight ratio, it changed f

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Parametric Study of Active Solar Heating Using a Pebble Bed as a Thermal Collector and Storage Unit
...Show More Authors

In this study, pebble bed as an absorber and storage material was placed in a south facing, flat plate air-type solar collector at fixed tilt angle of (45°). The effect of this material and differ- ent parameters on collector efficiency has been investigated experimentally and
theoretically. Two operation modes were employed to study the performance of the solar air heater. An inte- grated mode of continuous operation of the system during the period of (11:00 am – 3:00 pm) and non-integrated mode in which the system stored the solar energy through the day then used the stored energy during the period of (3:00 pm – 8:00 pm). The results of parametric study in case of continuous operating showed that the maximum average temperatur

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
Employing the indicators of stereotypes and the dimensions of organizational clarity and their role in achieving the planned organizational behavior Analytical study on a sample of workers in some departments of the Faculties of Engineering, University of
...Show More Authors

The current research examines the employment of indicators of stereotypes and the dimensions of organizational clarification to achieve planned organizational behaviour on a sample of employees in a number of departments of the Faculties of Engineering, University of Kufa, for a sample of (122) teaching staff. This research proposes the use of positive indicators of stereotypes for both the organization and employees and their awareness of what they want to obtain and what should be done for both parties and the removal of organizational clarity represented by the functional dimension that explores to what degree the employee's understanding of the internal strategy of the organization and the strategic dimension that searches fo

... Show More
View Publication Preview PDF
Crossref (1)
Crossref