METHOD AND DEVICE FOR STABILIZATION OF OPTICAL POWER …
1. A mode locked broadband ultrashort light pulse fiber oscillator based on nonlinear polarization rotation (NPR) of light comprising: a unidirectional fiber ring resonator operative to generate a train of ultrashort light pulses each having a broad range of frequencies, the fiber ring resonator including at least one light polarization controller unit; and an optoelectronic control feedback
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Monitoring the distributed impact wave on a concrete slab
Nov 27, 2007 · The impact wave is caused by the traffic passing on the highway pavement at high speed (>100 km h −1), which induced pressure on the concrete slabs, and in turn created a local birefringence change, leading to variation of the local state of polarization change (SOP). The pump and probe waves of the stimulated Brillouin scattering 'see' the
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Experimental study on structural defect detection by
May 24, 2019 · The method is developed on the basis of the pulse-pre-pump Brillouin optical time domain analysis (PPP-BOTDA) method [21]. It employs the dynamic distributed measurement capability of the PPP-BOTDA in order to sense the structural damage under in-service operations. The method enables simultaneous detection of many defects for many types of
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A set of measures for the systematic classification of the
Feb 25, 2015 · For the pump P we use the fundamental compressional mode of a rod‐shaped sample driven to strain amplitudes 10 −7 ≤ϵ P <10 −5. The probe (p) is a HF pulse (of low strain amplitude, ϵ p ≃10 −7) that tests the state of the sample at all phases of the pump strain field, i.e., in both compression and tension. From the behavior of the
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DAMAGE DETECTION TECHNIQUES FOR CONCRETE …
concrete pavements, and provides a wealth of data from a single measurement. Novel signal interpretation methods were developed for several important concrete applications. Detection of load-induced damage in a full-scale reinforced concrete column, as well as standard life-cycle damage in
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Pulse Diagnosis: How do we read the heart beat? (by Noah
Jul 30, 2009 · When taking the pulse the fingers can lie on the surface or press deeper to find different levels of the pulse. The change in the pressure on the vein, changes the meaning of the pulse. There are three levels of the pulse in this method. The first level is the superficial level, the way the pulse feels at the surface level of the wrist.
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Plasma optics in the context of high intensity lasers
Sep 23, 2019 · As we have seen in the initial stage (when the amplitude of the pump is much larger than that of the seed) the seed phase grows quickly while its amplitude does not change much. Indeed the seed phase grows as φ s ≃ 4 9 3 ( γ s c t ) 3, where γ sc depends on the amplitude of the pump …
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Evaluation of Concrete Structure Using Nondestructive
Mar 10, 2019 · The resulting amplitude spectrum is used to determine the condition of the concrete. The tests were conducted at the grid points of a 0.6 x 0.6-m grid in five selected areas of the tunnels.
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Pressure Pulsations Generated by - Warren Pumps LLC
The equation for determining the impeller vane passing frequency is: ) where IVP= ( 60 flvp— Impeller Vane Passing Frequency (hertz) Niv= Total Number of Vanes in the Impeller Speed of the Impeller (revolutions per minute) The above equation is used to determine the basic pulsation frequency for a single cutwater pump.
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DAMAGE DETECTION TECHNIQUES FOR CONCRETE …
concrete pavements, and provides a wealth of data from a single measurement. Novel signal interpretation methods were developed for several important concrete applications. Detection of load-induced damage in a full-scale reinforced concrete column, as well as standard life-cycle damage in
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(PDF) Methods to test and generate the wear load spectrum
Subsequently, the amplitude distribution of the wear load and its lasting time are extracted from the measured complex load-time history using the rain-flow counting method and Weibull distribution.
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Piezoelectric-based damage-depth monitoring method for
Jan 03, 2021 · The amplitude, pulse width, duration, and encoding bits of the pulse signal were 100 V, 15 µs, 30 µs, and 2, respectively. A data acquisition system with a sampling rate of 2 MHz was used to collect the signals received by the PZT sensors, and the data were transferred to PC software for storage via a category 6 UTP patch cord.
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Impact-Based Nonlinear Acoustic Testing for Characterizing
Jun 12, 2017 · Resonance-based methods, (linear) ultrasonic wave velocity and attenuation measurements and ultrasonic pulse-echo have long been adapted and used for concrete inspection. However, these conventional methods can only detect mm-size cracks, while showing no or little sensitivity to the accumulation of microcracks.
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Based on this theory, referring to FIGS. 2 and 7, the method for suppressing vibration of boom of concrete pump truck according to the present invention comprises the following steps: coupling a boom cylinder 2 with a vibration suppression cylinder 21; monitoring information about hydraulic pressure in the boom cylinder 2 and/or about changing of concrete pumping direction by pressure sensing units in real time; …
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Pipe Surge and Water Hammer Experiment - UKEssays.com
Water hammer is the formation of pressure waves as the result of a sudden change in liquid velocity in a piping system. Water hammer usually occurs when a fluid flow start or stops quickly or is forced to make a rapid change in direction. Quick closing of valves and stoppage of pump can create water hammer.
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TOPIC 2: FLOW IN PIPES AND CHANNELS
If the pump delivery pressure remains the same but a valve reduces the flow by half, find: (d) the head loss at the valve; (e) the power loss at the valve. Pump 8 m Barge Storage tank Control valve EXAMPLE SHEET, Q5 (a) A pipeline is to be constructed to bring water from an upland storage reservoir to a town 30 km away, at an elevation 150 m
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The demise of Concrete Pumping Companies based in Colorado
Apr 10, 2009 · The demise of Concrete Pumping Companies based in Colorado is due to the continuing decline of the pricing structure of the pumping industry. It seems like we are in a contest to see who will be the last one standing and who will receive a trophy for the last man standing before they also go by the wayside. Robinson gone â€" Pumpco gone â€" Lucht gone…Who will be the next one?
Learn MoreA multi-fault diagnosis method for piston pump in
May 01, 2013 · However, both methods mentioned above require new equipments with higher weight and volume of truck-mounted concrete pump which would remarkably increase the cost for the machinery. Therefore, our goal is to develop an automatic control method for the boom system which would be minimally disturbed by the vibration.
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From Fundamentals to Applications in Geotechnics doi:10
amplitude as the initial pulse, so the Beta method can be applied. Briefly, β is the rate of impedance change from Z2 to Z1 [4]: β = Z2 Z1 = 1 - α 1 + α (2) where: α is the damage amplitude divided by twice the amplitude of the initial pulse. Beta analysis only allows a crude estimate of the magnitude of the damage due to the
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Piezoelectric-based damage-depth monitoring method for
Jan 03, 2021 · The amplitude, pulse width, duration, and encoding bits of the pulse signal were 100 V, 15 µs, 30 µs, and 2, respectively. A data acquisition system with a sampling rate of 2 MHz was used to collect the signals received by the PZT sensors, and the data were transferred to PC software for storage via a category 6 UTP patch cord.
Learn More