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Time Domain Reflectometry Measurement of Water Content and Electrical Conductivity Using a Polyolefin Coated TDR ProbeMcIsaac, Gerald 18 May 2010 (has links)
The use of time domain reflectometry (TDR) to determine water content (θv) from the
measurement of the apparent dielectric constant (Ka) or the square root of the apparent dielectric
constant (Ka
0.5) in highly saline environments has been limited due to the dampening effect that
electrical conductivity (EC) has on the TDR signal. The objective of this research was to evaluate the
use of a three-rod TDR probe with a polyolefin coating on the center-conducting rod (CCRC probe)
to simultaneously measure θv and EC in saline conditions where standard, non-coated TDR probes
(NC probe) are ineffective.
The application of a 0.00053 m thick polyolefin coating on the center-conducting rod of a CS605
TDR probe increased the capability of the probe to measure θv at EC levels as high as 1.06 S m-1
compared to 0.132 S m-1 for a NC CS605 probe. The CCRC probe was found to be incapable of
determining any difference in EC levels. A 0.01 m long section or “gap” at the center of the
polyolefin coating on the center conducting rod (GAP probe) was cut from the polyolefin coating to
expose a section of the stainless steel center-conducting rod to allow direct contact with the material
being sampled. The GAP probe was found to be capable of measuring θv and EC at EC levels as high
as 0.558 S m-1.
Using a water-air immersion method, a comparison between the NC probe and the CCRC and
GAP probes was undertaken. The correlation between θv vs. Ka
0.5 was found to be linear for all three
probes with the slope (m) of the regressed equation for the NC probe (m = 7.71) being approximately
twice that of the CCRC probe (m = 4.25) and the GAP probe (m = 4.36). The intercept values were
equivalent for all three probes. The linearity between θv vs. Ka
0.5 for the NC and CCRC probes using
the water-air immersion method was also observed when the probes were used to measure Ka
0.5 of
different sand-water mixtures. The slope of regressed equation for the NC probe in the sand-water
iv
mixtures (m = 7.69) was equivalent to the water-air immersion slope for the NC probe, however the
intercept values for the sand-water mixtures was lower than the intercept values for the water-air
immersion method. Similarly, the slope of the CCRC probe in the sand-water mixtures (m = 5.00)
was equivalent to the CCRC probe water-air immersion slope. Calculated Ka
0.5 values using a waterair
dielectric-mixing model (WAMM) were equivalent to measured Ka
0.5 values for the NC probe.
The water air immersion method was found to provide a suitable methodology for TDR research,
however a more definitive test of the coated probe response in a series of soils with a range of
homogenous water contents should be completed to ascertain the reliability of the water-air
immersion method.
The straightforward relationship between the inverse of TDR measured impedance (ZL
-1) and EC
provided an effective calibration method for both the NC and GAP probes. The use of the Giese-
Tiemann method to establish a calibration curve for EC measurement was limited to a maximum EC
level of 0.132 S m-1 for the NC probe. The use of the cell constant method was considered to be
unacceptable as a means of developing a calibration curve due to the fact that the cell constant K was
not a constant value.
Ka
0.5 values for the CCRC and GAP were consistently less than Ka
0.5 values for the NC probe
at all qv levels except θv = 0.000 m3 m-3 or 100% air. The difference in Ka
0.5 (DKa
0.5) between the NC
probe and the CCRC and GAP probes was seen to increase with increasing water content. Similarly, a
measurable effect was found between the TDR waveforms for the NC probe when the probe head was
surrounded completely by air when compared to the TDR waveforms for the NC probe when the
probe head was completely surrounded by water. Modeled electrostatic fields for the NC and CCRC
CS605 TDR probes displayed a decrease in the electric potential and electric field intensity in the
region outside of the polyolefin coating of the CCRC probe compared to the NC probe. The decrease
v
in potential and electric field intensity became greater when the dielectric constant of the material
surrounding the CCRC probe increased.
The use of a polyolefin coating on the center-conducting rod with a small section of the
coating removed at the midsection of rod provides an effective means of extending the application of
TDR θv and EC measurement in saline environments where standard TDR probes cannot be used.
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Data Bus Deskewing Systems in Digital CMOS TechnologyAtrash, Amer Hani 13 May 2004 (has links)
This dissertation presents a study of signal deskewing systems in standard CMOS technologies. The objective of this work is to understand the limitations of deskewing systems as they are applied to modern systems and present new architectures to overcome past limitations. Traditional methods for signal deskewing are
explored and the general limitations of these methods are identified. Several new architectures are proposed to address the limitations of previous techniques. The
systems will be investigated with regard to minimum resolution, programming time,
delay, maximum data rate, full scale range, and duty cycle distortion. Several other
effects that are critical to the operation of deskewing systems will also be investigated.
These effects include overshoot caused by parasitic package inductance, the impact
of capacitive terminations, and the effect of mutual inductance between traces.
To fulfill the requirements of this study, two deskewing systems are implemented
in a 0.25um process. An open-loop system for deskewing wide data busses and a
closed-loop system for deskewing a differential pair of lines are both fabricated. Both
systems are found to meet the expected performance metrics, providing validation of
the proposed techniques. Use of the proposed architectures allows the limitations of
previous methods to be overcome. The remaining work is validated through either analytical techniques, simulations, or both where appropriate.
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Equivalent Model Extracting by the Least-square Estimation Method in Time Domain MeasurementHo, Wen-Bo 01 July 2000 (has links)
Equivalent model extracting by the least-square estimation method and optimation in time domain measurement.It discuss at the effect of step soure rising and how to use TDR measurements in high speed digital system.It can determine characteristic impedances of DUT,compute accurate models for inductance and capacitance,and predict interconnect component more accurately.
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Time Domain Reflectometry Measurement of Water Content and Electrical Conductivity Using a Polyolefin Coated TDR ProbeMcIsaac, Gerald 18 May 2010 (has links)
The use of time domain reflectometry (TDR) to determine water content (θv) from the
measurement of the apparent dielectric constant (Ka) or the square root of the apparent dielectric
constant (Ka
0.5) in highly saline environments has been limited due to the dampening effect that
electrical conductivity (EC) has on the TDR signal. The objective of this research was to evaluate the
use of a three-rod TDR probe with a polyolefin coating on the center-conducting rod (CCRC probe)
to simultaneously measure θv and EC in saline conditions where standard, non-coated TDR probes
(NC probe) are ineffective.
The application of a 0.00053 m thick polyolefin coating on the center-conducting rod of a CS605
TDR probe increased the capability of the probe to measure θv at EC levels as high as 1.06 S m-1
compared to 0.132 S m-1 for a NC CS605 probe. The CCRC probe was found to be incapable of
determining any difference in EC levels. A 0.01 m long section or “gap” at the center of the
polyolefin coating on the center conducting rod (GAP probe) was cut from the polyolefin coating to
expose a section of the stainless steel center-conducting rod to allow direct contact with the material
being sampled. The GAP probe was found to be capable of measuring θv and EC at EC levels as high
as 0.558 S m-1.
Using a water-air immersion method, a comparison between the NC probe and the CCRC and
GAP probes was undertaken. The correlation between θv vs. Ka
0.5 was found to be linear for all three
probes with the slope (m) of the regressed equation for the NC probe (m = 7.71) being approximately
twice that of the CCRC probe (m = 4.25) and the GAP probe (m = 4.36). The intercept values were
equivalent for all three probes. The linearity between θv vs. Ka
0.5 for the NC and CCRC probes using
the water-air immersion method was also observed when the probes were used to measure Ka
0.5 of
different sand-water mixtures. The slope of regressed equation for the NC probe in the sand-water
iv
mixtures (m = 7.69) was equivalent to the water-air immersion slope for the NC probe, however the
intercept values for the sand-water mixtures was lower than the intercept values for the water-air
immersion method. Similarly, the slope of the CCRC probe in the sand-water mixtures (m = 5.00)
was equivalent to the CCRC probe water-air immersion slope. Calculated Ka
0.5 values using a waterair
dielectric-mixing model (WAMM) were equivalent to measured Ka
0.5 values for the NC probe.
The water air immersion method was found to provide a suitable methodology for TDR research,
however a more definitive test of the coated probe response in a series of soils with a range of
homogenous water contents should be completed to ascertain the reliability of the water-air
immersion method.
The straightforward relationship between the inverse of TDR measured impedance (ZL
-1) and EC
provided an effective calibration method for both the NC and GAP probes. The use of the Giese-
Tiemann method to establish a calibration curve for EC measurement was limited to a maximum EC
level of 0.132 S m-1 for the NC probe. The use of the cell constant method was considered to be
unacceptable as a means of developing a calibration curve due to the fact that the cell constant K was
not a constant value.
Ka
0.5 values for the CCRC and GAP were consistently less than Ka
0.5 values for the NC probe
at all qv levels except θv = 0.000 m3 m-3 or 100% air. The difference in Ka
0.5 (DKa
0.5) between the NC
probe and the CCRC and GAP probes was seen to increase with increasing water content. Similarly, a
measurable effect was found between the TDR waveforms for the NC probe when the probe head was
surrounded completely by air when compared to the TDR waveforms for the NC probe when the
probe head was completely surrounded by water. Modeled electrostatic fields for the NC and CCRC
CS605 TDR probes displayed a decrease in the electric potential and electric field intensity in the
region outside of the polyolefin coating of the CCRC probe compared to the NC probe. The decrease
v
in potential and electric field intensity became greater when the dielectric constant of the material
surrounding the CCRC probe increased.
The use of a polyolefin coating on the center-conducting rod with a small section of the
coating removed at the midsection of rod provides an effective means of extending the application of
TDR θv and EC measurement in saline environments where standard TDR probes cannot be used.
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Uso das técnicas HCT e TDR no monitoramento do proceso de consolidação em reservatórios de barragens de rejeitos / Monitoring of consolidation process in deposits of tailings dam by TDR and HCT techniquesVagner Albuquerque de Lima 25 September 2009 (has links)
A indústria de mineração gera uma vasta quantidade de rejeitos que são comumente depositados em reservatórios ou lagoas de contenção. Para dimensionar adequadamente estas construções, quando o rejeito é altamente compressível, é necessário estudar as características de consolidação deste material através de técnicas que contemplem grandes deformações. Este trabalho teve como objetivo implantar a técnica HCT (Hydraulic Consolidation Test) nos laboratórios do departamento de Geotecnia da EESC-USP e consolidar a utilização da técnica TDR (Time Domain Reflectometry). Também teve como objetivo avaliar o processo de consolidação de rejeitos argilosos contidos em uma barragem com o uso de técnicas de laboratório (HCT) e de campo (TDR). Nos ensaios de laboratório foi utilizada a técnica HCT, enquanto que em campo foi utilizada a técnica TDR. Em laboratório, realizaram-se ensaios com amostras coletadas na região do vertedouro e do canal de lançamento de rejeitos. Foram realizadas diversas análises com estas amostras utilizando a técnica HCT, tendo como resultado uma pequena variação nos parâmetros de consolidação obtidos. Através destes parâmetros foi calculada a curva de compressibilidade de laboratório. A técnica TDR fez uso de uma sonda desenvolvida especialmente para este fim, sendo realizada uma calibração previa em laboratório com o material da barragem. A técnica TDR apresentou, de forma instantânea, a estimativa do teor de umidade para as sondagens realizadas na barragem de rejeitos. Com os resultados da técnica TDR, os índices de vazios foram calculados por correlações e, por fim, calculadas as tensões efetivas atuantes em cada profundidade estudada, gerando uma curva de compressibilidade de campo. Pode-se então comparar as curvas de compressibilidade de laboratório e campo obtendo-se uma grande proximidade entre os valores. Conclui-se que ambas as técnicas são validas para avaliação do processo de consolidação de materiais moles em barragens de rejeitos. / The mining industry generates a large amount of tailing, which is usually placed in tailing dams. To properly design these constructions, when the tailing is highly compressible, it is necessary to study the consolidation characteristics of this material by means of techniques that consider large deformations. This study aimed to establish the technique HCT (Hydraulic Consolidation Test) in the laboratories of the department of Geotechnical Engineering, EESC-USP and consolidate the use of the technique TDR (Time Domain Reflectometry). This research work also aimed to evaluate the process of consolidation of clayey tailings through laboratory and field tests. For laboratory tests it was used the Hydraulic Consolidation Test (HCT) whereas field tests used the Time Domain Reflectometry (TDR) technique. The laboratory tests were carried out with samples collected in the spillway and next to the discharge spigot. Several analyses were performed using the HCT technique. The analysis results showed very little variations in the consolidation parameter values. The compressibility curve was determined using these consolidation parameters. The TDR tests were carried out using a probe specifically designed for this purpose. Laboratory calibration was performed with samples collected in the dam. One advantage of the TDR technique is to provide in real time estimates of the soil water content. With the water content profiles provided by the TDR technique, void ratio and effective stress profiles were determined using correlations obtained in laboratory, enabling to find a field compressibility curve. Then, the laboratory and field compressibility curves were compared, showing them very close to each other. It was concluded that both techniques are valid for evaluating the process of consolidation of soft materials in tailings dams.
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Uso das técnicas HCT e TDR no monitoramento do proceso de consolidação em reservatórios de barragens de rejeitos / Monitoring of consolidation process in deposits of tailings dam by TDR and HCT techniquesLima, Vagner Albuquerque de 25 September 2009 (has links)
A indústria de mineração gera uma vasta quantidade de rejeitos que são comumente depositados em reservatórios ou lagoas de contenção. Para dimensionar adequadamente estas construções, quando o rejeito é altamente compressível, é necessário estudar as características de consolidação deste material através de técnicas que contemplem grandes deformações. Este trabalho teve como objetivo implantar a técnica HCT (Hydraulic Consolidation Test) nos laboratórios do departamento de Geotecnia da EESC-USP e consolidar a utilização da técnica TDR (Time Domain Reflectometry). Também teve como objetivo avaliar o processo de consolidação de rejeitos argilosos contidos em uma barragem com o uso de técnicas de laboratório (HCT) e de campo (TDR). Nos ensaios de laboratório foi utilizada a técnica HCT, enquanto que em campo foi utilizada a técnica TDR. Em laboratório, realizaram-se ensaios com amostras coletadas na região do vertedouro e do canal de lançamento de rejeitos. Foram realizadas diversas análises com estas amostras utilizando a técnica HCT, tendo como resultado uma pequena variação nos parâmetros de consolidação obtidos. Através destes parâmetros foi calculada a curva de compressibilidade de laboratório. A técnica TDR fez uso de uma sonda desenvolvida especialmente para este fim, sendo realizada uma calibração previa em laboratório com o material da barragem. A técnica TDR apresentou, de forma instantânea, a estimativa do teor de umidade para as sondagens realizadas na barragem de rejeitos. Com os resultados da técnica TDR, os índices de vazios foram calculados por correlações e, por fim, calculadas as tensões efetivas atuantes em cada profundidade estudada, gerando uma curva de compressibilidade de campo. Pode-se então comparar as curvas de compressibilidade de laboratório e campo obtendo-se uma grande proximidade entre os valores. Conclui-se que ambas as técnicas são validas para avaliação do processo de consolidação de materiais moles em barragens de rejeitos. / The mining industry generates a large amount of tailing, which is usually placed in tailing dams. To properly design these constructions, when the tailing is highly compressible, it is necessary to study the consolidation characteristics of this material by means of techniques that consider large deformations. This study aimed to establish the technique HCT (Hydraulic Consolidation Test) in the laboratories of the department of Geotechnical Engineering, EESC-USP and consolidate the use of the technique TDR (Time Domain Reflectometry). This research work also aimed to evaluate the process of consolidation of clayey tailings through laboratory and field tests. For laboratory tests it was used the Hydraulic Consolidation Test (HCT) whereas field tests used the Time Domain Reflectometry (TDR) technique. The laboratory tests were carried out with samples collected in the spillway and next to the discharge spigot. Several analyses were performed using the HCT technique. The analysis results showed very little variations in the consolidation parameter values. The compressibility curve was determined using these consolidation parameters. The TDR tests were carried out using a probe specifically designed for this purpose. Laboratory calibration was performed with samples collected in the dam. One advantage of the TDR technique is to provide in real time estimates of the soil water content. With the water content profiles provided by the TDR technique, void ratio and effective stress profiles were determined using correlations obtained in laboratory, enabling to find a field compressibility curve. Then, the laboratory and field compressibility curves were compared, showing them very close to each other. It was concluded that both techniques are valid for evaluating the process of consolidation of soft materials in tailings dams.
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Control de Gestión y Preservación Control de gestión y preservación vial, caso: corredor vial "Santa-Yuracmarca-Sihuas-Huacrachuco-San pedro de Chonta-Uchiza-Emp. Pe 5n y puente Huarochiri-Huallanca-Molinopampa", tramo: puente Huarochiri-SihuasGiraldo Ruiz, Arthur F. January 2015 (has links)
Uno de los objetivos primordiales de la conservación vial, es “evitar al máximo posible la pérdida del capital ya invertido, mediante la protección física de la estructura básica y de la superficie del camino”. Esto se consigue primordialmente brindando un mantenimiento de tipo rutinario y periódico que evita la destrucción de la estructura de los caminos y posterior rehabilitación o reconstrucción.
La presente tesis, está elaborada en base a investigación por un lado y por el otro lado aplicativo, la Parte de investigación corresponde a la información teórica recopilada, en las visitas que se realizarán a organismos viales en nuestro país: Ministerio de transporte, Provias Nacional y Provias Rural y de manera muy significativa la información que recibo en el área donde laboro. En cuanto a la parte aplicativa, es aquí donde se pone en práctica la parte conceptual de la tesis y para ello el tramo que sirvió de aplicación, el tramo Pte. Huarochiri – Sihuas.
Después del mantenimiento rutinario y periódico a la vía se realizará una evaluación con el Software HDM-4, donde nos indicará que el IRI promedio estará en el rango admisible en los próximos 4 años, donde requerirá realizar trabajos rutinarios durante esos años y en el quinto año se tendrá que realizar un TSB (Tratamiento superficial bicapa) debido al aumento del IMD.
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台灣存託憑證與原標的股股價關聯性與短期績效之研究 / Research of the relationship and the short-term performance between Taiwan depository receipts and underlying stock郭乙萱 Unknown Date (has links)
2008年以來,台灣證券交易所大力推動海外企業來台發行台灣存託憑證(TDR),除促進台灣股票市場的國際化外,也希望提供海外台商有更多、更便利的籌資管道,致使這兩年來在台發行存託憑證之公司家數急遽上升,使TDR的發行造成話題。
因此本研究以TDR作為研究對象,探討台灣股市與亞太地區主要市場之間是否存在長期均衡以及因果關係,並且進一步檢視國外公司來台發行存託憑證是否對標的股的股價造成異常報酬。採用的研究方式為利用單根檢定、共整合以及誤差修正模型來檢視兩市場間的因果關係和影響方向;並利用事件研究法探討原上市市場的投資人是否對公司在台發行存託憑證給予正面反應。
結果發現TDR股價與原標的股股價之間大多存在共整合,兩市場間有一長期均衡。另採用誤差修正模型測試發現,大多數標的股股價對TDR股價具有影響,存在單向因果關係,反之則不然。投資人可利用原上市市場的股價及相關訊息來做為投資TDR的參考依據,惟必須注意兩市場間重大訊息發佈時間的不一致所造成的資訊不對稱風險。
另外,利用事件研究法來探討公司發行台灣存託憑證是否產生異常報酬,結果顯示原上市市場的投資人對於企業來台發行存託憑證多持正面看法,即表示對台灣股票市場具有一定的信心和信任。
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The Impact of Stock Price Manipulation for the Price Difference among Taiwan, China and Hong Kong Stock MarketWen, Chung-yu 21 June 2010 (has links)
Taking advantage of proxy variable of stock price manipulation like ownership concentration and earning management to examine the price difference between two market. In addition to liquidity or demand elasticity,etc, using manipulate variable of premium market(A-shares compared to H-share,TDR compared to HK-share) to investigate if manipulation can explain stock price difference.
Empricial results show that premium not only concern to market system, but also connect to manipulation factors.The degree of premium will decrease as time progressd.
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Design of a Multilevel - TDR Probe for Measuring Soil Water ContentAdelakun, Idris Ademuyiwa 30 November 2012 (has links)
ABSTRACT
The TDR measures soil water content by measuring the travel time of an electromagnetic step pulse through a wave guide embedded in the soil. Damage during insertion and retrieval of the probe makes it unsuitable for repeated use. A multilevel-TDR probe with adequate protection for cable was designed and tested to overcome this problem.
Each section of the multilevel-TDR probe was constructed by embedding a 60 mm centre rod and a 63 mm outer loop in grooves on the outer wall of a 200 mm section of PVC pipe. Fifteen such probes were tested in the laboratory and the field by comparing it with the weighing method. Regression analysis between TDR-ϴv and weighing method-ϴv showed good correlation with an R2 of 0.97 and 0.98 during two laboratory experiments and 0.51 during the field experiment. This multilevel probe is cost effective, reusable and can measure soil water content at different depths.
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