An Assessment of Module Cooling Enhancement With Thermoelectric Coolers

2005 ◽  
Vol 127 (1) ◽  
pp. 76-84 ◽  
Author(s):  
R. E. Simons ◽  
M. J. Ellsworth ◽  
R. C. Chu
Keyword(s):  
Figure Of Merit ◽  
Early History ◽  
Multichip Module ◽  
Thermoelectric Cooler ◽  
Thermoelectric Figure ◽  
Thermoelectric Coolers ◽  
Chip Temperature ◽  
Recent Developments ◽  
Cooling Enhancement ◽  
History Of

The trend towards increasing heat flux at the chip and module level in computers is continuing. This trend coupled with the desire to increase performance by reducing chip operating temperatures presents a further challenge to thermal engineers. This paper will provide an assessment of the potential for module cooling enhancement with thermoelectric coolers. A brief background discussion of thermoelectric cooling is provided citing some of the early history of thermoelectrics as well as more recent developments from the literature. An example analyzing cooling enhancement of a multichip module package with a thermoelectric cooler is discussed. The analysis utilizes closed form equations incorporating both thermoelectric cooler parameters and package level thermal resistances to relate allowable module power to chip temperature. Comparisons are made of allowable module power with and without thermoelectric coolers based upon either air or water module level cooling. These results show that conventional thermoelectric coolers are inadequate to meet the requirements. Consideration is then given to improvements in allowable module power that might be obtained through increases in the thermoelectric figure of merit ZT or miniaturization of the thermoelectric elements.

An Assessment of Module Cooling Enhancement With Thermoelectric Coolers

2003 ◽  
Author(s):  
R. E. Simons ◽  
M. J. Ellsworth ◽  
R. C. Chu
Keyword(s):  
Figure Of Merit ◽  
Early History ◽  
Thermoelectric Cooler ◽  
Thermoelectric Figure ◽  
Thermo Electric ◽  
Thermoelectric Coolers ◽  
Chip Temperature ◽  
Recent Developments ◽  
Cooling Enhancement ◽  
History Of

The trend towards increasing heat flux at the chip and module level in computers is continuing. This trend coupled with the desire to increase performance by reducing chip operating temperatures presents a further challenge to thermal engineers. This paper will provide an assessment of the potential for module cooling enhancement with thermoelectric coolers. A brief background discussion of thermo-electric cooling is provided citing some of the early history of thermoelectrics as well as more recent developments from the literature. An example analyzing cooling enhancement of a multi-chip module package with a thermoelectric cooler is discussed. The analysis utilizes closed form equations incorporating both thermoelectric cooler parameters and package level thermal resistances to relate allowable module power to chip temperature. Comparisons are made of allowable module power with and without thermoelectric coolers based upon either air or water module level cooling. These results show that conventional thermoelectric coolers are inadequate to meet the requirements. Consideration is then given to improvements in allowable module power that might be obtained through increases in the thermoelectric figure of merit ZT or miniaturization of the thermoelectric elements.

scholarly journals A Review: Electrospinning and Electrospinning Nanofibre Technology, Process & Application

2020 ◽  
Vol 5 (6) ◽  
pp. 528-538
Author(s):  
Somesh S. Bhagure ◽  
Dr. Adarsh R. Rao
Keyword(s):  
Electronic Devices ◽  
Early History ◽  
Comprehensive Overview ◽  
Thin Fiber ◽  
Filtration Membranes ◽  
Technology Process ◽  
Recent Developments ◽  
History Of ◽  
Catalytic Supports ◽  
Remarkable Progress

Electrospinning is a versatile and viable technique for ultra-thin fiber generation. Remarkable progress has been made with regard to the development of Electrospinning methods and the engineering of Electrospinning Nanofibre to suit or enable different applications. We aim to provide a comprehensive overview of Electrospinning, including principles, methods, materials and applications. We begin with a brief introduction to the early history of Electrospinning, followed by a discussion of its principle and its typical apparatus. Subsequently, we discuss the applications of electrospun Nanofibre, including their use as smart mattresses, filtration membranes, catalytic supports, energy harvesting / conversion / storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent developments in the application of electrospun Nanofibre by focusing on the most representative examples.

The History of the Global Anti-Human Trafficking Agenda, with a Focus on Prostitution and Sexual Exploitation

2021 ◽  
pp. 151-161
Author(s):  
Heli Askola
Keyword(s):  
Human Trafficking ◽  
Sexual Exploitation ◽  
Early History ◽  
White Slavery ◽  
Government Organizations ◽  
Trafficking In Women ◽  
Recent Developments ◽  
History Of ◽  
Women And Children ◽  
International Instruments

Heli Askola examines the early history of international instruments for the suppression of the trafficking in women and children involved in so called ‘white slavery’ as precursors to the more recent developments relating to human trafficking. She challenges the notion of the linear progression in the development of the law and illustrates that the contests between various NGOs and government organizations meant that this development was neither smooth nor uncontested.

scholarly journals Joseph Delboeuf on time as the mechanism of free will

2021 ◽  
pp. 095935432110231
Author(s):  
André R. LeBlanc
Keyword(s):  
Energy Conservation ◽  
Free Will ◽  
Early History ◽  
Conservation Of Energy ◽  
First Law Of Thermodynamics ◽  
Before And After ◽  
Recent Developments ◽  
History Of ◽  
The Law ◽  
Two Bodies

In the early 1880s, Joseph Delboeuf proposed a little-known but ingenious solution to the problem the law of the conservation of energy poses for free will. When energy is transferred between two bodies, the law of energy conservation requires that the energy before and after the transfer be the same, but it says nothing of the time it must take. If we could delay this transfer, Delboeuf proposed, we could alter the course of matter without compromising the conservation of energy. This article begins by tracing the early history of the conflict between free will and the first law of thermodynamics and by recounting some initial attempts to resolve it. It next describes Delboeuf’s theory and the arguments that were made against it, before situating it with respect to some recent developments in the philosophy and psychology of free will.

scholarly journals Влияние термической предыстории на свойства эффективных термоэлектрических сплавов Ge-=SUB=-0.86-=/SUB=-Pb-=SUB=-0.1-=/SUB=-Bi-=SUB=-0.04-=/SUB=-Te-=SUP=-*-=/SUP=-

2022 ◽  
Vol 56 (3) ◽  
pp. 261
Author(s):  
А.А. Шабалдин ◽  
А.Ю. Самунин ◽  
П.П. Константинов ◽  
С.В. Новиков ◽  
А.Т. Бурков ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Structural Modification ◽  
Lattice Thermal Conductivity ◽  
Partial Substitution ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Maximum Value ◽  
History Of ◽  
Simultaneous Decrease ◽  
Good Agreement

In this work, we study the properties of GeTe -based alloys, doped with bismuth, with partial substitution of lead for germanium: Ge0.86Pb0.1Bi0.04Te. The aim of the study is to explore the possibility of increasing the thermoelectric efficiency of a compound by combining optimal doping and isovalent substitution to improve the electronic properties with a simultaneous decrease of the lattice thermal conductivity. We studied alloy samples prepared in two different research laboratories using similar, but not completely identical procedures. It is shown that the electronic (thermoelectric power and electrical conductivity) properties of the samples of the two groups are in good agreement with each other. The properties of alloys depend on the thermal history of the samples due to the presence at temperatures of 600–800 K of a phase transition from a low-temperature rhombohedral to a high-temperature cubic structural modification. The thermoelectric figure of merit of alloys reaches a maximum value of 1.5 at a temperature of about 750 K.

scholarly journals Криогенный термоэлектрический модуль для рабочего интервала температур ниже 90 K

2019 ◽  
Vol 53 (6) ◽  
pp. 761
Author(s):  
Н.А. Сидоренко ◽  
З.М. Дашевский
Keyword(s):  
Figure Of Merit ◽  
High Temperature Superconductor ◽  
Temperature Drop ◽  
Cooling Capacity ◽  
Electrical Circuit ◽  
Cryogenic Temperatures ◽  
Thermoelectric Figure ◽  
Thermoelectric Coolers ◽  
Maximum Value ◽  
A Current

It is considered the possibility of creating thermoelectric coolers for operating temperatures below 90 K. For these temperatures it is not possible to use a standard circuit of a thermoelement, consisting of two n- and p-semiconductor legs, connected in a series electrical circuit. In the area of cryogenic temperatures there is only an effective thermoelectric material of n-type conductivity, based on solid solutions Bi−Sb. In this case thermoelements composed of thermoelectric n-type leg and a passive leg, based on high temperature superconductor (HTSC) were studied. A thermoelectric cooler (module), consisting of six n-type legs (extruded crystals Bi0.91Sb0.09 ) and passive legs based on HTSC (YBa2Cu3O(7−x) ) films was designed. A magnetic field was used to increase thermoelectric figure of merit ZT of the cryogenic module. For created cryogenic module at hot side temperature Th = 80 K, a current I = 6.4 A and a voltage U = 0.10 V the maximum value of temperature drop > 13.5 K and a maximum cooling capacity Qc > 0.36 W were achieved.

The Scanning Hot Probe Technique for Seebeck Coefficient Characterization

2006 ◽  
Author(s):  
Claudiu L. Hapenciuc ◽  
Theodorian Borca-Tasciuc
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
State Of The Art ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Energy ◽  
Recent Developments ◽  
Hot Probe

Highly efficient solid-state thermoelectric energy conversion requires materials with a large thermoelectric figure of merit Z=σα2/κ where α=thermoelectric power, σ=electrical conductivity, and κ=thermal conductivity [1]. Engineering the electric and thermal transport in nanostructures has emerged as a candidate for factorial enhancements in the thermoelectric figure of merit, as compared with state of the art bulk thermoelectric materials.[2-5] Recent developments in thermoelectric materials are reviewed in Ref [4]. These studies have sparked a flurry of activity to produce nanostructures for thermoelectric applications.

Combined Power Plants—Past, Present, and Future

1995 ◽  
Vol 117 (4) ◽  
pp. 608-616 ◽  
Author(s):  
J. H. Horlock
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Early History ◽  
Future Prospects ◽  
Recent Developments ◽  
History Of

The early history of combined power plants is described, together with the birth of the CCGT plant (the combined “cycle” gas turbine). Sustained CCGT development in the 1970s and 1980s, based on sound thermodynamic considerations, is outlined. Finally more recent developments and future prospects for the combined gas turbine/steam turbine combined plant are discussed.

The Effect of Quantum Well Structures on the Thermoelectric Figure of Merit

1992 ◽  
Vol 281 ◽  
Author(s):  
L. D. Hicks ◽  
M. S. Dresselhaus
Keyword(s):  
Quantum Well ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Thermoelectric Coolers ◽  
Quantum Well Structures ◽  
Thermoelectric Refrigeration ◽  
Superlattice Structures ◽  
Materials Used ◽  
Made In

ABSTRACTCurrently the materials with the highest thermoelectric figure of merit, Z, are Bi2Te3 alloys. Therefore these compounds are the best thermoelectric refrigeration elements. However, since the 1960's only slow progress has been made in enhancing Z, either in Bi2Te3 alloys or in other thermoelectric materials. So far, the materials used in applications have all been in bulk form. In this paper, it is proposed that it may be possible to increase Z of certain materials by preparing them in quantum well superlattice structures. Calculations have been done to investigate the potential for such an approach, and also to evaluate the effect of anisotropy on the figure of merit. The calculations show that layering has the potential to increase significantly the figure of merit of a highly anisotropic material like Bi2Te3, provided that the superlattice multilayers are made in a particular orientation. This result opens the possibility of using quantum well superlattice structures to enhance the performance of thermoelectric coolers.

Some early history of replica techniques for electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1076-1077
Author(s):  
Robert M. Fisher
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Optical Microscope ◽  
Early History ◽  
Bulk Materials ◽  
Thin Sections ◽  
Transmission Electron ◽  
Reflected Light ◽  
History Of ◽  
Electron Microscopes

By 1940, a half dozen or so commercial or home-built transmission electron microscopes were in use for studies of the ultrastructure of matter. These operated at 30-60 kV and most pioneering microscopists were preoccupied with their search for electron transparent substrates to support dispersions of particulates or bacteria for TEM examination and did not contemplate studies of bulk materials. Metallurgist H. Mahl and other physical scientists, accustomed to examining etched, deformed or machined specimens by reflected light in the optical microscope, were also highly motivated to capitalize on the superior resolution of the electron microscope. Mahl originated several methods of preparing thin oxide or lacquer impressions of surfaces that were transparent in his 50 kV TEM. The utility of replication was recognized immediately and many variations on the theme, including two-step negative-positive replicas, soon appeared. Intense development of replica techniques slowed after 1955 but important advances still occur. The availability of 100 kV instruments, advent of thin film methods for metals and ceramics and microtoming of thin sections for biological specimens largely eliminated any need to resort to replicas.

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