Reference liquids for the calibration of dielectric sensors and measurement instruments

Kaatze, U.

doi:10.1088/0957-0233/18/4/002

Cited by 147 publications

(106 citation statements)

References 96 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The pore fluid as well as the interface fluid can be considered as an aqueous solution with a temperaturepressure-frequency-dependent relative complex permittivity ε * W (ω, T , p) according to the modified Debye model (Kaatze, 2007a) as a special case of the GDR according to Eq. (5) with N = 1, a i = 0 and b i = 1:…”

Section: Dielectric Soil Propertiesmentioning

confidence: 99%

Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

Lorek

Wagner

2013

The Cryosphere

View full text Add to dashboard Cite

Abstract.Water substantially affects nearly all physical, chemical and biological processes on the Earth. Recent Mars observations as well as laboratory investigations suggest that water is a key factor of current physical and chemical processes on the Martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid-like state of water on Martian analogue soils for temperatures below 0 • C. To this end, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine-grained soils in the frequency range from 10 Hz to 1.1 MHz at Martian-like temperatures down to −70 • C. Two Martian analogue soils have been investigated: a Ca-bentonite (specific surface of 237 m 2 g −1 , up to 9.4 % w/w gravimetric water content) and JSC Mars 1, a volcanic ash (specific surface of 146 m 2 g −1 , up to 7.4 % w/w). Three soil-specific relaxation processes are observed in the investigated frequency-temperature range: two weak highfrequency processes (bound or hydrated water as well as ice) and a strong low-frequency process due to counter-ion relaxation and the Maxwell-Wagner effect. To characterize the dielectric relaxation behaviour, a generalized fractional dielectric relaxation model was applied assuming three active relaxation processes with relaxation time of the ith process modelled with an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid-like water content by means of the Birchak or CRIM equation. There are evidence that bentonite down to −70 • C has a liquid-like water content of 1.17 monolayers and JSC Mars 1 a liquid-like water content of 1.96 monolayers.

show abstract

Section: Dielectric Soil Propertiesmentioning

confidence: 99%

Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

Lorek

Wagner

2013

The Cryosphere

View full text Add to dashboard Cite

show abstract

“…Esse parâmetro é importante para o projeto de reatores, pois fornece uma indicação sobre a dimensão da cavidade a ser construída em função da frequência utilizada. 36 Segundo Metaxas e Meredith (1983), 55 a distância de penetração para um meio não-magnético é,…”

Section: Equnclassified

“…O projeto adequado necessariamente passaria pela caracterização dielétrica do material, simulação eletromagnética da estrutura, construção e teste do sistema completo. 55  Possibilidade de uso de maior temperatura reacional.…”

Section: Reações Químicas Induzidas Por Mo Em Meio Glicerólicounclassified

“…Este último caso em particular, é importante por ser a origem do fenômeno chamado de fuga térmica, uma vez que, no aquecimento dielétrico, o que caracteriza a fuga térmica é o aumento do fator de perda concomitantemente com a temperatura. 55 Isso acarreta um aumento na absorção de energia das MO pelo meio reacional, que acarreta outro aumento de temperatura, que aumenta o fator de perda novamente e assim sucessivamente. Com isso, forma-se um ciclo sinérgico que dificulta o controle da temperatura e do processo reacional.…”

unclassified

See 1 more Smart Citation

Glycerochemistry Topics: Use of Glycerol as a Green Solvent in Microwave-assisted Reactions

Campos

Santos²,

Borges³

2017

Rev. Virtual Quim.

View full text Add to dashboard Cite

Abstract:The glycerol is a triol whose supply in market is in continuous growth due to the biodiesel industry, since its formation occurs concomitantly with the latter. From this arises the need to find applications for glycerol that absorb all this new quantity produced. One of the applications that has emerged in the literature, is the use of glycerol as solvent or co-solvent in chemical processes. Solvents are used in chemical processes to aid in mass and heat transfer phenomena, to facilitate separation, purification, etc. Since glycerol has interesting physicochemical and dielectric properties, furthermore renewable origin, and the microwave technology is proving greener than the current ones, a conjunction of both shows a desirable synergistic situation. Therefore, the contribution of this work is to realize a review the literature highlighting examples of applications, where this synergistic situation is present.Keywords: Glycerol; solvent; microwaves; dielectric properties; microwave-assisted chemistry; green chemistry. ResumoO glicerol é um triol cuja oferta no mercado se encontra em crescimento contínuo por ser produzido como subproduto na indústria do biodiesel. Disso surge a necessidade de se encontrar aplicações para o glicerol que absorvam toda esta nova quantidade produzida. Uma das aplicações que vem despontado na literatura, é a utilização do glicerol como solvente ou co-solvente em processos químicos. Solventes são utilizados em processos químicos para auxiliar fenômenos de transferência de massa e de calor, facilitar separações, purificações, etc. Uma vez que o glicerol possui propriedades físico-químicas e dielétricas interessantes, além da origem renovável, e a tecnologia de micro-ondas estar se provando mais verde que as colocadas atualmente, uma conjunção de ambos se mostra uma situação sinérgica desejável. Logo, a contribuição deste trabalho é fazer uma revisão da literatura destacando exemplos de aplicações, onde esta situação sinérgica está presente.

show abstract

“…Energy sources that have been investigated for delivering hyperthermia with non-invasive applicators include capacitive [9] and inductive [10] radiofrequency devices, microwave antennas [11] and focused ultrasound. The clinical treatment goal is to raise the targeted tumour temperature to [41][42][43][44][45] C and deliver thermal doses of 6-10 min at 43 C for 90% of the measured points (CEM43T90) [4,12].…”

Section: Introductionmentioning

confidence: 99%

Design of a compact antenna with flared groundplane for a wearable breast hyperthermia system

Curto

Prakash

2015

International Journal of Hyperthermia

View full text Add to dashboard Cite

Purpose: Currently available microwave hyperthermia systems for breast cancer treatment do not conform to the intact breast and provide limited control of heating patterns, thereby hindering an effective treatment. A compact patch antenna with a flared groundplane that may be integrated within a wearable hyperthermia system for the treatment of the intact breast disease is proposed. Materials and methods: A 3D simulation-based approach was employed to optimise the antenna design with the objective of maximising the hyperthermia treatment volume (41 C iso-therm) while maintaining good impedance matching. The optimised antenna design was fabricated and experimentally evaluated with ex vivo tissue measurements. Results: The optimised compact antenna yielded a À10 dB bandwidth of 90 MHz centred at 915 MHz, and was capable of creating hyperthermia treatment volumes up to 14.4 cm 3 (31 mm Â 28 mm Â 32 mm) with an input power of 15 W. Experimentally measured reflection coefficient and transient temperature profiles were in good agreement with simulated profiles. Variations of + 50% in blood perfusion yielded variations in the treatment volume up to 11.5%. When compared to an antenna with a similar patch element employing a conventional rectangular groundplane, the antenna with flared groundplane afforded 22.3% reduction in required power levels to reach the same temperature, and yielded 2.4 times larger treatment volumes. Conclusion:The proposed patch antenna with a flared groundplane may be integrated within a wearable applicator for hyperthermia treatment of intact breast targets and has the potential to improve efficiency, increase patient comfort, and ultimately clinical outcomes. KeywordsBreast cancer treatment, flared groundplane, microwave hyperthermia, patch antenna, wearable medical devices History

show abstract

Reference liquids for the calibration of dielectric sensors and measurement instruments

Cited by 147 publications

References 96 publications

Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

Glycerochemistry Topics: Use of Glycerol as a Green Solvent in Microwave-assisted Reactions

Design of a compact antenna with flared groundplane for a wearable breast hyperthermia system

Contact Info

Product

Resources

About