Preferred Language
Articles
/
6xaZHooBVTCNdQwCHJAn
A review of ultra-high temperature materials for thermal protection system
...Show More Authors
Abstract<p>Ultra-High Temperature Materials (UHTMs) are at the base of entire aerospace industry; these high stable materials at temperatures exceeding 1600 °C are used to manage the heat shielding to protect vehicles and probes during the hypersonic flight through reentry trajectory against aerodynamic heating and reducing plasma surface interaction. Those materials are also recognized as Thermal Protection System Materials (TPSMs). The structural materials used during the high-temperature oxidizing environment are mainly limited to SiC, oxide ceramics, and composites. In addition to that, silicon-based ceramic has a maximum-use at 1700 °C approximately; as it is an active oxidation process over low temperature and water vapor environment condition. However, a great emphasis is required for developing structural materials in oxidation and rapid heating environment where the temperature is greater than 1700 °C. This review covers briefly all main types of Thermal Protection Systems (TPSs) and all the materials are used to fabricate them with the maximum operational temperatures. Also, it covers the promised UHTMs (SiC, ZrB<sub>2</sub>, HfB<sub>2</sub>, SiB<sub>6</sub> and B<sub>4</sub>C) which are currently using for several aerospace applications, especially for TPS. Besides, it discusses the oxidation of SiC, B<sub>4</sub>C, SiB<sub>6</sub>, ZrB<sub>2</sub> and HfB<sub>2</sub>. Therefore, the carbides and borides of the transition metals, Zr and Hf have a high-melting temperature and good stability in forming high-melting temperature oxides.</p>
Scopus Clarivate Crossref
View Publication
Publication Date
Sat Mar 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect of Carbon Fiber Volume Fraction and their Orientations on the Thermal Conductivity of the Polymer Composite Materials.
...Show More Authors

      The effect of fiber volume fraction of the carbon fiber on the thermal conductivity of the polymer composite material was studied. Different percentages of carbon fibers were used (5%, 10%, 15%, 20%, and 25%). Specimens were made in two groups for unsaturated polyester as a matrix and carbon fibers, first group has parallel arrangement of fibers and the second group has perpendicular arrangement of fibers on the thermal flow, Lee's disk method was used for testing the specimens. This study showed that the values of the of thermal conductivity of the specimens when the fibers arranged in parallel direction was higher than that when the fibers arranged in the perpendicular direction  

 &nbsp

... Show More
View Publication Preview PDF
Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Study of weathering effect on the thermal conductivity of polyvinyl chloride before and after silicon carbide addition as packaging materials
...Show More Authors

The work was carried out in two stages. The first stage concerned
with study of silicon carbide (SiC) ratio (1.5, 2.5, 3.5, and 4.5 wt%)
effect on the Thermal conductivity of polyvinyl chloride (PVC); and
the second stage concerned with the UV – weatherizing (25, 50, and
75 hr), thermal aging (40, 50, and 60 °C), and rain- weatherizing (1,
2.5, and 4 hr) effect on the samples involved. Thermal conductivity
results proved that there was slight increase in thermal conductivity
by (SiC) loading; it increased from 0.17 W/m.K for PVC to 0.19
W/m.K for 4.5% SiC/PVC; where as it was systematically decreased
by UV- weatherizing, thermal aging, and rain- weatherizing. This
property is in a good agreement with gene

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
Application of Wavelet Packet and S Transforms for Differential Protection of Power Transformer
...Show More Authors

The differential protection of power transformers appears to be more difficult than any type of protection for any other part or element in a power system. Such difficulties arise from the existence of the magnetizing inrush phenomenon. Therefore, it is necessary to recognize between inrush current and the current arise from internal faults. In this paper, two approaches based on wavelet packet transform (WPT) and S-transform (ST) are applied to recognize different types of currents following in the transformer. In WPT approach, the selection of optimal mother wavelet and the optimal number of resolution is carried out using minimum description length (MDL) criteria before taking the decision for the extraction features from the WPT tree

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Oct 01 2010
Journal Name
Iraqi Journal Of Physics
Effect of the Thickness and Annealing Temperature on the Structural Properties of Thin CdS Films Prepared by Thermal Evaporation
...Show More Authors

A thin CdS Films have been evaporated by thermal evaporation technique with different thicknesses (500, 1000, 1500 and 2000Å) and different duration times of annealing (60, 120 180 minutes) under 573 K annealing temperature, the vacuum was about 8 × 10-5 mbar and substrate temperature was 423 K. The structural properties of the films have been studied by X- ray diffraction technique (XRD). The crystal growth became stronger and more oriented as the film thickness (T) and duration time of annealing ( Ta) increases.

View Publication Preview PDF
Publication Date
Mon May 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Studied Some of the Thermal and Electrical Properties for Particulat Polymer Composites
...Show More Authors

  This researchs the preparation of particulate polymer composites from Alkyd resin and Iraqi Burn Kaolin which were added as (20%,30%,40%,50%)and comparing  with the  polymer.  It studied Thermal conductivity and Dielectric strength for both of  the Alkyd resin and  the Composite Material.        The result showed an  increase in Dielectric strength after adding the Iraqi Burn Kaolin , also the Thermal conductivity was  increased by adding the Iraqi Burn Kaolin .

View Publication Preview PDF
Publication Date
Wed Jul 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Subject Review on Some Analytical Methods for Determination of Fosfomycin Drugs
...Show More Authors

Medicines comprising fosfomycin are prescribed for urinary tract infections. These drugs are available for oral use as tromethamine and calcium, while fosfomycin-sodium and disodium are given for intravenous (IV) and intramuscular (IM). Many quantitative analytical methods have been reported to estimate Fosfomycin in blood, urine, plasma, serum, and pharmaceutical dosage formulations. Some techniques were spectrophotometric, mass spectrometry, gas chromatography, high-performance liquid chromatography, and electrochemical methods. Here we perform a rapid narrative review that discusses and comparison between them of various analytical methods for the determination of Fosfomycin-containing drugs.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Mar 05 2025
Journal Name
Lecture Notes In Networks And Systems
Leveraging AI for Disaster Management: A Comprehensive Review of Applications and Challenges
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Tue Jul 02 2013
Journal Name
Journal Of Baghdad College Of Dentistry
Local Drug Delivery Systems for Treating Periodontal Diseases: A Review of Literature
...Show More Authors

Publication Date
Sat Jun 07 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Local drug delivery systems for treating periodontal diseases (A review of literature)
...Show More Authors

In this review of literature, the light will be concentrated on the local drugs delivery systems for treating the periodontal diseases. Principles, types, advantages and indications of each type will be discussed in this paper.

View Publication Preview PDF
Publication Date
Mon Apr 01 2024
Journal Name
Al-kindy College Medical Journal
Radiological Modalities for the Assessment of Fetal Growth Restriction: A Comprehensive Review
...Show More Authors

Fetal growth restriction is a significant contributor to fetal morbidity and mortality. In addition, there are heightened maternal risks associated with surgical operations and their accompanying dangers. Monitoring fetal development is a crucial objective of prenatal care and effective methods for early diagnosis of Fetal growth restriction, allowing prompt management and timely intervention to improve the outcomes. Screening for Fetal growth restriction can be achieved via many modalities; it can be medical, biochemical, or radiological. Some recommended combining more than one for better outcomes. Currently, there is inconsistency about the best method of Fetal growth restriction screening.   In this review, a comprehensive

... Show More
Scopus (7)
Crossref (9)
Scopus Crossref