scholarly journals A practical method for in-situ thermal characterization of walls

2016 ◽  
Vol 8 ◽  
pp. 84-93 ◽  
Author(s):  
Emilio Sassine
Keyword(s):  
Thermal Characterization ◽  
Practical Method

scholarly journals In situ thermal characterization of existing buildings aiming at NZEB standard: A methodological approach

2020 ◽  
Vol 2 ◽  
pp. 100008
Author(s):  
Luca Evangelisti ◽  
Claudia Guattari ◽  
Francesco Asdrubali ◽  
Roberto de Lieto Vollaro
Keyword(s):  
Methodological Approach ◽  
Thermal Characterization ◽  
Existing Buildings

scholarly journals Processing and Characterization of Silicon Nitride Nanofiber Paper

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Kei-Peng Jen ◽  
Ronald Warzoha ◽  
Ji Guo ◽  
Michael Tang ◽  
Sridhar Santhanam
Keyword(s):  
Silicon Nitride ◽  
Thermal Insulation ◽  
Reduction Process ◽  
Thermal Characterization ◽  
Nitride Phase ◽  
Mechanical Stiffness ◽  
Precursor Material ◽  
Processing Step

Papers of silicon nitride nanofibers were synthesized by a carbothermal reduction process. These nanofiber papers were synthesized in situ and did not require a secondary processing step. The process utilized silica nanopowders and silica gel as the precursor material. Processing geometry played a crucial role in regulating the growth of the nanofiber papers. Characterization of the nanofiber papers indicated that the nanofibers were of the alpha silicon nitride phase. Both mechanical stiffness and strength of the nanofiber papers were measured. Thermal conductivity and specific heat of the papers were also measured and were found to be lower than many common thermal insulation materials at much smaller thicknesses and were comparable to those values that are typically reported for carbon-nanotube-based buckypaper. Results of the mechanical and thermal characterization indicate that these silicon nitride nanofiber papers can be utilized for specialized thermal insulation applications.

Thermal characterization of coal using piezoelectric photoacoustic microscopy

1986 ◽  
Vol 64 (9) ◽  
pp. 1184-1189 ◽  
Author(s):  
A. Biswas ◽  
T. Ahmed ◽  
K. W. Johnson ◽  
K. L. Telschow ◽  
J. C. Crelling ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Characterization ◽  
Photoacoustic Signal ◽  
Photoacoustic Microscopy ◽  
Piezoelectric Detection ◽  
Theoretical Predictions ◽  
Coal Macerals

The organic constituents that make up the heterogeneous coal mass are called macerals. Vitrinite and pseudovitrinite are two of the most abundantly occurring macerals in North American coals. Photoacoustic microscopy using piezoelectric detection offers a useful technique for probing the thermal-elastic properties of these coal macerals. The experimental and theoretical conditions under which photoacoustic microscopy can be used to characterize the in situ thermal-elastic properties of macerals, as a function of the percentage of carbon or "rank" of coal, are investigated in this paper. Existing piezoelectric photoacoustic theory has been applied to our sample–transducer configuration to arrive at an expression for the voltage measured from the piezoelectric transducer. The theory indicates that the photoacoustic signal is related to the following sample properties: coefficient of thermal expansion a, bulk modulus B, density ρ, and specific heat c. These properties are coupled together into a dimensionless parameter given by aB/ρc, to which the measured voltage is proportional. Some experimental results used to test the validity of the theoretical predictions are presented. Photoacoustic data gathered on 10 Appalachian Basin coals are plotted as a function of the coal rank. These results are shown to compare favourably with a calculated curve, constructed using independently measured values of a, B, ρ, and c.

Determination of the crystal structure of nifedipine form C by synchrotron powder diffraction

2011 ◽  
Vol 67 (4) ◽  
pp. 357-364 ◽  
Author(s):  
Mauro Bortolotti ◽  
Ivan Lonardelli ◽  
Giancarlo Pepponi
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Molecular Conformation ◽  
Thermal Characterization ◽  
Powder Diffraction Data ◽  
Synchrotron Powder Diffraction ◽  
Metastable Form

The crystal structure of the metastable form C polymorph of nifedipine [C17H18N2O6, 3,5-dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate] was determined by means of direct-space techniques applied to high-resolution synchrotron powder diffraction data. The polymorph crystallizes in the space group P\bar 1 and exhibits a molecular packing significantly different from that of the stable modification, with molecules aligned in an orthogonal configuration inside the unit cell. The molecular conformation, on the other hand, remains substantially unmodified between the two polymorphs. Additionally, in situ thermal characterization of nifedipine crystallization behaviour was performed, confirming the nucleation of another metastable polymorph (form B) prior to the complete crystallization of the stable modification. A complete structural characterization of form B was not possible owing to its very limited stability interval.

Electrical Characterization and Failure Analysis Using Operando TEM

2017 ◽  
Author(s):  
Yevheniy Pivak ◽  
H.H. Perez-Garza ◽  
Alexander Zintler ◽  
Leopoldo Molina-Luna
Keyword(s):  
Failure Analysis ◽  
Microelectromechanical Systems ◽  
Real Life ◽  
Electrical Characterization ◽  
Thermal Characterization ◽  
Semiconductor Materials ◽  
Transmission Electron ◽  
Ideal Method

Abstract We present here the development of a system that allows for in-situ studies inside the Transmission Electron Microscope (TEM). Functionalized Microelectromechanical Systems (MEMS) used as sample carriers, referred to as Nano-Chips, contain up to eight electrodes used for simultaneous biasing and heating purposes, enabling electro-thermal characterization of various sample types inside the TEM under real life dynamic conditions. This operando approach is an ideal method to study failure analysis of semiconductor materials, performance of resistive switching devices, batteries, fuel cells, piezoceramics and many more.

Application of Frequency-Domain Thermal Measurements in Electronics Packaging

2009 ◽  
Author(s):  
Yizhang Yang ◽  
Zhen Zhang ◽  
Maxat Touzelbaev
Keyword(s):  
Frequency Domain ◽  
Hot Spot ◽  
Thermal Structure ◽  
Semiconductor Industry ◽  
Thermal Characterization ◽  
Practical Method ◽  
Component Level ◽  
Spot Detection ◽  
Advanced Packaging

Increase of power densities has become the primary constraint for semiconductor industry to sustain the Moore’s law for microprocessor evolution. Further development of packaging technology and advanced thermal interface materials (TIMs) requires both maximization of the total thermal throughput of the system and mitigation of the thermal impact from non-uniformly distributed hotspots. Therefore, thermal characterization techniques capable of resolving partial thermal resistances at the component level have received increased emphasis in development of advanced packaging technologies. This work develops a practical method for thermal characterization of IC packages using the frequency-domain measurement technique. It is well suited for investigation of package thermal performance during various application-specific tests in field conditions, as well as a tool for development of TIM and optimization of packaging process. Both steady-state and dynamic thermal characterizations of the IC packages can be achieved using this technique. Various applications, such as thermal structure function measurement, silicon die hot-spot detection, and in-situ thermal/mechanical characterization of TIMs are discussed.

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