Low temperature limitation on the quality factor of quartz resonators

1994 ◽  
Vol 41 (2) ◽  
pp. 250-255 ◽  
Author(s):  
A. El Habti ◽  
F.O. Bastien
Keyword(s):  
Low Temperature ◽  
Quality Factor ◽  
Temperature Limitation ◽  
Quartz Resonators

Performance Improvement of RF Inductors Using LTCC Technology

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000054-000058 ◽  
Author(s):  
Goran Radosavljević ◽  
Andrea Marić ◽  
Walter Smetana ◽  
Ljiljana Živanov
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Design Optimization ◽  
Quality Factor ◽  
Performance Improvement ◽  
Air Gap ◽  
Frequency Range ◽  
Operating Frequency Range ◽  
Rf Inductors ◽  
First Time

This paper presents for the first time a parallel comparison of the performance of RF inductors realized on different substrate configurations. Presented inductors are meander type structures fabricated in Low Temperature Co-fired Ceramic (LTCC) technology. Also, chosen material is never before implemented for inductor fabrication. The performance improvement is achieved by design optimization of different substrate configurations that incorporate placement of an air-gap beneath the inductor and/or introduction of an additional shielding layer on the top. Designed structures are characterized on the basis of simulation and experimental data, achieving good correlation between obtained results. Presented results show over 30 % increase in quality factor and widening of the operating frequency range by over 55 %.

Low-temperature limitation of primary photosynthetic processes in Antarctic lichens Umbilicaria antarctica and Xanthoria elegans

Polar Biology ◽  
2007 ◽  
Vol 31 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Miloš Barták ◽  
Peter Váczi ◽  
Josef Hájek ◽  
Jerzy Smykla
Keyword(s):  
Low Temperature ◽  
Temperature Limitation

Effect of BaCu(B2O5) on the sintering temperature and microwave dielectric properties of Ba(Nd0.8Bi0.2)2Ti4O12 ceramics

2010 ◽  
Vol 25 (12) ◽  
pp. 2380-2383 ◽  
Author(s):  
Yi Zeng ◽  
Hong Wang ◽  
Huanfu Zhou
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Potential Candidate ◽  
Microwave Dielectric ◽  
Quality Factor Q

The effect of BaCu(B2O5) (BCB) on the sintering temperature and microwave dielectric properties of Ba(Nd0.8Bi0.2)2Ti4O12 (BNBT) ceramics was investigated. The sintering temperature of the BNBT ceramics was significantly reduced from 1300 to 900 °C. Due to adding BCB into Ba(Nd1–xBix)2Ti4O12, the temperature coefficient of resonant frequency can be adjusted to zero with BCB content increasing. Good microwave dielectric properties of quality factor (Q×f) = 2600 GHz, εr = 75, and τf = 5 ppm/°C were obtained for BNBT with 7 wt% BCB sintered at 925 °C for 2 h, which make it a potential candidate for low temperature cofired ceramics applications.

scholarly journals Low-temperature limitation of bioreactor sludge in anaerobic treatment of domestic wastewater

2013 ◽  
Vol 69 (5) ◽  
pp. 1004-1013 ◽  
Author(s):  
Emma J. Bowen ◽  
Jan Dolfing ◽  
Russell J. Davenport ◽  
Fiona L. Read ◽  
Thomas P. Curtis
Keyword(s):  
Low Temperature ◽  
Domestic Wastewater ◽  
Temperature Limit ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Anaerobic Reactors ◽  
Theoretical Yield ◽  
Lower Temperature Limit ◽  
Temperature Limitation ◽  
Lower Temperature

Two strategies exist for seeding low-temperature anaerobic reactors: the use of specialist psychrophilic biomass or mesophilic bioreactor sludge acclimated to low temperature. We sought to determine the low-temperature limitation of anaerobic sludge from a bioreactor acclimated to UK temperatures (<15 °C). Anaerobic incubation tests using low-strength real domestic wastewater (DWW) and various alternative soluble COD sources were conducted at 4, 8 and 15 °C; methanogenesis and acidogenesis were monitored separately. Production of methane and acetate was observed; decreasing temperature resulted in decreased yields and increased ‘start-up’ times. At 4 °C methanogenesis not hydrolysis/acidogenesis was rate-limiting. The final methane yields at 4 °C were less than 35% of the theoretical potential whilst at 8 and 15 °C more than 75 and 100% of the theoretical yield was achieved respectively. We propose that the lower temperature limit for DWW treatment with anaerobic bioreactor sludge lies between 8 and 4 °C and that 8 °C is the threshold for reliable operation.

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