• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Zum Einsatz neuer Thermometerhütten

Schienbein, Sigurd 25 October 2016 (has links) (PDF)
Die Verkleinerung der modernen Temperatursensoren ermöglicht die Volumenreduzierung der bisher angewandten Stevenson-Wetterhütten. Insbesondere bei automatischen Stationen finden wir wesentlich kleinere Strahlungsschutzeinrichtungen. Langjährige Beobachtungsreihen sind nicht mehr vergleichbar und müssen angepaßt werden. Es werden Einzelwertabweichungen für Temperaturen von mehr als 1 K genannt. Zur Lösung dieses Problems sind Vergleichsuntersuchungen und Anpassungsrechnungen erforderlich. / The minimisation of modern temperature sensors allows to reduce the volume ofthe up to now used Stevenson screens. Especially for automatic stations we found essential smaller radiationshields. Temperature observations of many years arc incomperable and had to be adapted. Errors of more as 1 K for single temperatures are mentioned. For the solution of this problem comparisons and adaptations are necessary.
2

Zum Einsatz neuer Thermometerhütten

Schienbein, Sigurd 25 October 2016 (has links)
Die Verkleinerung der modernen Temperatursensoren ermöglicht die Volumenreduzierung der bisher angewandten Stevenson-Wetterhütten. Insbesondere bei automatischen Stationen finden wir wesentlich kleinere Strahlungsschutzeinrichtungen. Langjährige Beobachtungsreihen sind nicht mehr vergleichbar und müssen angepaßt werden. Es werden Einzelwertabweichungen für Temperaturen von mehr als 1 K genannt. Zur Lösung dieses Problems sind Vergleichsuntersuchungen und Anpassungsrechnungen erforderlich. / The minimisation of modern temperature sensors allows to reduce the volume ofthe up to now used Stevenson screens. Especially for automatic stations we found essential smaller radiationshields. Temperature observations of many years arc incomperable and had to be adapted. Errors of more as 1 K for single temperatures are mentioned. For the solution of this problem comparisons and adaptations are necessary.
3

Carbonaceous Nanofillers and Poly(3,4-ethylenedioxythiophene) Poly(styrenesulfonate) Nanocomposites for Wireless Sensing Applications

Benchirouf, Abderrahmane 07 January 2019 (has links)
The current state of wireless sensing technologies possesses a good reliability in terms of time response and sensing on movable parts or in embedded structures. Nevertheless, these tech- nologies involve energy supply such as battery and suffer from low resolution and bulky signal conditioning system for data processing. Thus, a RFID passive wireless sensor is a good candidate to overcome these issues. The feasibility of implementing microstrip patch antennas for sensing application were successfully investigated; however, low sensitivity was always a big issue to be concerned. Sensors based on nanocomposites attracted a lot of attention because of their excellent performance in term of light weight, high sensitivity, good stability and high resistance to corrosion but it lacks the capability of high conductivity, which limit their implication into RFID applications. This work introduces a novel high sensitive passive wireless strain and temperature sensors based on nanocomposites as sensing layer. To accomplish this, intrinsically conductive polymer based on carbon nanofillers nanocomposites are deeply studied and characterized. Then it’s performance is evaluated. Among them a novel tertiary nanocomposite is introduced, which opens the gate to new nanocomposite applications and thus broad- ens the application spectrum. Understanding the transport mechanism to improve the conductivity of the nanocomposite and extracting individually different models based on physical explanation of their piezoresistivity, and behavior under temperature and humidity have been developed. Afterwards, selected nanocomposites based on their high sensitivity to either strain or temperature are chosen to be used as sensing layer for patch antenna. The fabricated patch antenna has only one fundamental frequency, by determining the shift in its resonance frequency as function of the desired property to be measured; the wireless sensor characteristics are then examined. For strain sensing, the effect of strain is tested experimentally with the help of end-loaded beam measurement setup. For temperature sensing, the sensors are loaded in a controlled temperature/humid chamber and with the help of a vector network analyzer, the sensitivity of the antennas are extracted by acquiring the shift in the resonance frequency. The fabricated wireless sensors based on patch antenna are fabricated on very low lossy material to improve their gain and radiation pattern. This approach could be expanded also to include different type of substrates such as stretchable substrates i.e. elastomer polymer, very thing substrates such as Kapton, paper-based substrates or liquid crystal polymer.

Page generated in 0.0814 seconds