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
Fri Mar 01 2024
Journal Name
Baghdad Science Journal
Study the Structural Properties of Porous Silicon and their Applications as Thermal Sensors
...Show More Authors

The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm2 current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for et

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jun 07 2015
Journal Name
Baghdad Science Journal
Synthesis, Characterization, Thermal Analysis and Structural Studies of New Complexes with Tetradentate Ligand
...Show More Authors

Some new complexes of 4-(5-(1,5-dimethyl-3-oxo-2-phenyl pyrazolidin-4- ylimino)-3,3-dimethyl cyclohexylideneamino) -1,5- dimethyl-2- phenyl -1H- pyrazol -3(2H) –one (L) with Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) were prepared. The ligand and its metal complexes were characterized by phisco- chemical spectroscopic techniques. The spectral data were suggested that the (L) as a neutral tetradentate ligand is coordinated with the metal ions through two nitrogen and two oxygen atoms. These studies revealed Octahedral geometries for all metal complexes, except square planar for Pd(II) complex. Moreover, the thermodynamic activation parameters, such as ?E*, ?H, ?S, ?G and K are calculated from the TGA curves using Coa

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2010
Journal Name
Advances In Condensed Matter Physics
Electrical and Optical Properties of :H Thin Films Prepared by Thermal Evaporation Method
...Show More Authors

Thin a-:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As), and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on value

... Show More
View Publication
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Oct 13 2021
Journal Name
Egyptian Journal Of Chemistry
Synthesis and Characterization and Thermal Properties of New Linked Azo-Phenol-Formaldehyde Resins
...Show More Authors

View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2009
Journal Name
Iraqi Journal Of Physics
Preparation Cadmium Telluride Compound and Study Structural Properties of thermal evaporation thin films
...Show More Authors

Polycrystalline ingots of cadmium telluride have been synthesized using the direct
reaction technique, by fusing initial component consisting from pure elements in
stoichiometric ratio inside quartz ampoule is evacuated 10-6 torr cadmium telluride has
been grown under temperature at (1070) oC for (16) hr. was used in this study, the phases
observed in growing CdTe compound depend on the temperature used during the growth
process. Crystallography studies to CdTe compound was determined by X-ray diffraction
technique, which it has zinc blend structure and cubic unit cell, which lattice constants is
a=6.478
oA

View Publication Preview PDF
Publication Date
Wed Sep 30 2009
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Prediction of Effective Bed Thermal Conductivity and Heat Transfer Coefficient in Fluidized Beds
...Show More Authors

Experimental study of heat transfer coefficients in air-liquid-solid fluidized beds were carried out by measuring the heat rate and the overall temperature differences across the heater at different operating conditions. The experiments were carried out in Q.V.F. glass column of 0.22 m inside diameter and 2.25 m height with an axially mounted cylindrical heater of 0.0367 m diameter and 0.5 m height. The fluidizing media were water as a continuous phase and air as a dispersed phase. Low density (Ploymethyl-methacrylate, 3.17 mm size) and high density (Glass beads, 2.31 mm size) particles were used as solid phase. The bed temperature profiles were measured axially and radially in the bed for different positions. Thermocouples were connecte

... Show More
View Publication Preview PDF
Publication Date
Tue Sep 01 2015
Journal Name
2015 Ieee International Circuits And Systems Symposium (icsys)
Investigating the impact of on-chip interconnection noise on Dynamic Thermal Management efficiency
...Show More Authors

Dynamic Thermal Management (DTM) emerged as a solution to address the reliability challenges with thermal hotspots and unbalanced temperatures. DTM efficiency is highly affected by the accuracy of the temperature information presented to the DTM manager. This work aims to investigate the effect of inaccuracy caused by the deep sub-micron (DSM) noise during the transmission of temperature information to the manager on DTM efficiency. A simulation framework has been developed and results show up to 38% DTM performance degradation and 18% unattended cycles in emergency temperature under DSM noise. The finding highlights the importance of further research in providing reliable on-chip data transmission in DTM application.

View Publication
Scopus (2)
Scopus Crossref
Publication Date
Sat Aug 31 2024
Journal Name
International Review On Modelling And Simulations (iremos)
Thermal Buckling Analysis of Composite Laminated Shells Using Higher Order Shear Deformation Theory
...Show More Authors

View Publication
Scopus (2)
Scopus Crossref
Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
The Effects of micro Aluminum fillers In Epoxy resin on the thermal conductivity
...Show More Authors

View Publication
Scopus (37)
Crossref (26)
Scopus Clarivate Crossref
Publication Date
Mon Mar 30 2026
Journal Name
Iraqi Journal Of Science
Analyzing Materials and Determining their Physical Properties Using Spectral Sensing Technology from Satellite Images: Methodology and Applications
...Show More Authors

The spectral remote sensor technology was used to study the Kurdistan region of Iraq to determine the characteristics of surface minerals and by analyzing satellite images across multiple spectral ranges, distinctive spectral signatures were specified for several metals such as zinc (ZN), Lead (PB), and Parium (BA), as well as the use of thermal infrared to detect free abnormalities and the results were verified through field measurements and admonitory, where the selection accuracy was 85% according to the absolute error (MAPE) and 0.045 for RMSé and the results showed that spectral signatures for metals were distributed in nearby and remote IR ranges, helping to determine mineral sediments such as zinc and lead in carbonate rocks

... Show More
View Publication
Scopus Crossref