Experimental investigation of nonlinear operation mode of a DP-QPSK 100G link with co-propagating-pump Raman amplification

2018 ◽  
Vol 48 (8) ◽  
pp. 767-772
Author(s):  
D.D. Starykh ◽  
I.I. Shikhaliev ◽  
V.A. Konyshev ◽  
O.E. Nanii ◽  
V.N. Treshchikov ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Operation Mode ◽  
Raman Amplification ◽  
Nonlinear Operation

scholarly journals Molecular photoswitches mediating the strain-driven disassembly of supramolecular tubules

2017 ◽  
Vol 114 (45) ◽  
pp. 11850-11855 ◽  
Author(s):  
Jean W. Fredy ◽  
Alejandro Méndez-Ardoy ◽  
Supaporn Kwangmettatam ◽  
Davide Bochicchio ◽  
Benjamin Matt ◽  
...  
Keyword(s):  
Essential Feature ◽  
Operation Mode ◽  
Building Blocks ◽  
Water Soluble ◽  
Atomistic Simulations ◽  
Supramolecular Architecture ◽  
Mechanical Responses ◽  
Pulling Forces ◽  
Nonlinear Operation ◽  
Insight Into

Chemists have created molecular machines and switches with specific mechanical responses that were typically demonstrated in solution, where mechanically relevant motion is dissipated in the Brownian storm. The next challenge consists of designing specific mechanisms through which the action of individual molecules is transmitted to a supramolecular architecture, with a sense of directionality. Cellular microtubules are capable of meeting such a challenge. While their capacity to generate pushing forces by ratcheting growth is well known, conversely these versatile machines can also pull microscopic objects apart through a burst of their rigid tubular structure. One essential feature of this disassembling mechanism is the accumulation of strain in the tubules, which develops when tubulin dimers change shape, triggered by a hydrolysis event. We envision a strategy toward supramolecular machines generating directional pulling forces by harnessing the mechanically purposeful motion of molecular switches in supramolecular tubules. Here, we report on wholly synthetic, water-soluble, and chiral tubules that incorporate photoswitchable building blocks in their supramolecular architecture. Under illumination, these tubules display a nonlinear operation mode, by which light is transformed into units of strain by the shape changes of individual switches, until a threshold is reached and the tubules unleash the strain energy. The operation of this wholly synthetic and stripped-down system compares to the conformational wave by which cellular microtubules disassemble. Additionally, atomistic simulations provide molecular insight into how strain accumulates to induce destabilization. Our findings pave the way toward supramolecular machines that would photogenerate pulling forces, at the nanoscale and beyond.

Experimental Investigation of the Starting Procedure of a Helicopter Gas Turbine Featuring an Impingement Quick-Start System

2020 ◽  
Author(s):  
Niklas Kuen ◽  
Volker Gümmer
Keyword(s):  
Experimental Investigation ◽  
Gas Turbine ◽  
Operation Mode ◽  
Significant Loss ◽  
Fuel Saving ◽  
Engine Operation ◽  
Air Mass ◽  
Parameter Variations ◽  
Air Impingement ◽  
Startup Time

Abstract Intended Single Engine Operation (ISEO) offers fuel saving potential for twin engine helicopters but the shut-off of one engine implies safety concerns. Due to the restart time of the gas turbine the helicopter will experience a significant loss of altitude which limits the safe envelope where ISEO is applicable. In this paper, an air impingement system, which is capable of reducing the startup time of the engine by about 60 % to 80 %, is investigated experimentally. Different parameter variations are carried out to minimize the amount of air which is necessary to accelerate the engine in order to reduce the overall weight and size of the system. The modifications to the process are elaborated for startup of the engine to ground idle and to flight operation mode. For startup to ground idle the impinged air mass could be reduced by 25 % without having drawbacks in startup time.

scholarly journals Numerical and experimental investigation on the transient behavior of an earth air heat exchanger in continuous operation mode

2017 ◽  
Vol 35 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Yousef Belloufi ◽  
Abdelhafid Brima ◽  
Sakina Zerouali ◽  
Rachid Atmani ◽  
Faris Aissaoui ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Heat Exchanger ◽  
Operation Mode ◽  
Transient Behavior ◽  
Continuous Operation

Experimental investigation of chirp pulse Raman amplification in plasma

2011 ◽  
Author(s):  
X. Yang ◽  
G. Vieux ◽  
E. Brunetti ◽  
J. P. Farmer ◽  
B. Ersfeld ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Chirp Pulse ◽  
Raman Amplification

Certain Features of Interaction Between Laser Radiation and Metals

2020 ◽  
pp. 15-32
Author(s):  
A.N. Glotov ◽  
Yu.V. Golubenko ◽  
V.A. Desyatskov ◽  
A.V. Stepanov
Keyword(s):  
Experimental Investigation ◽  
Laser Radiation ◽  
Continuous Wave ◽  
Operation Mode ◽  
Single Pulse ◽  
Radiation Energy ◽  
Parameter Variation ◽  
Laser Operation ◽  
Radiation Energy Density ◽  
Interaction Efficiency

The paper presents experimental investigation results concerning the problem of optimising the efficiency of interaction between laser radiation and metals. We used several types of Nd lasers featuring the desired combination of power, temporal and spatial radiation parameters as sources of the radiation required. To pump these lasers, we employed rectangular pulses at a periodicity eliminating effects characteristic of continuous-wave and pulsed laser operation modes. This limits the laser radiation parameters driving the interaction efficiency functions to strictly those parameters that match the single-pulse laser operation mode. Temporal radiation parameter variation involved measurements in the free-running and high-frequency Q-switching modes as well as adjusting pumping (lasing) pulse durations. Power parameter variation was implemented through altering radiation energy density over the irradiated surface. Spatial structure of the ablative radiation was varied by means of optical radiation transfer facilities and different laser emitters. The experimental investigation results allowed us to establish certain patterns concerning the interaction between laser radiation and metals as a function of radiation parameters listed

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