scholarly journals Application of new turbulent method for determining vertical refraction

2021 ◽  
Vol 11 (1) ◽  
pp. 102-110
Author(s):  
S. A. Younes
Keyword(s):  
Turbulent Atmosphere ◽  
Measurement Accuracy ◽  
New Method ◽  
Temperature Stratification ◽  
Total Station ◽  
Automatic Guidance ◽  
The Creation ◽  
Conventional Methods

Abstract This paper is concerned with the study of new turbulent method technique for the determining of vertical refraction when total stations are used. Required measurement accuracy of vertical refraction by conventional methods is extremely difficult due to rapid random changes in the angle of refraction. Geodetic observations are recommended to performing only during periods of indifferent temperature stratification, while the refraction is close to zero and practically unvaried. However, this period is extremely short and its boundaries are not defined, so the inefficiency of all known methods for determining refraction must be attention. The complete liberation of geodetic observations from the influence of turbulent and fluctuation processes in the atmosphere is possible only by directly measuring the angle of refraction at the time of observation. The creation of electronic total stations with automatic guidance to the target allows to successfully solving the problem of determining refraction by a turbulent method. The aim of this work is to study the new method for determining refraction in a turbulent atmosphere. The measurements are performed with a Trimble total station. The obtained results confirm that the accuracy for determining refraction is ~2″, which almost corresponds to the instrumental accuracy of the device used.

Vertical refraction determination using a Trimble S9 total station

2020 ◽  
Vol 954 (12) ◽  
pp. 2-9
Author(s):  
D.V. Dementiev ◽  
I.M. Zhukov ◽  
M.Y. Karavanov ◽  
I.I. Ranov ◽  
N.Yu. Litvinov
Keyword(s):  
Atmospheric Turbulence ◽  
Turbulent Atmosphere ◽  
Measurement Accuracy ◽  
Dynamic Method ◽  
Experimental Studies ◽  
High Accuracy ◽  
Measuring Instruments ◽  
Total Station ◽  
The Real

Classical methods for determining refraction are based on Newton’s formulae for a statically stable atmosphere. However, they do not provide the required measurement accuracy due to random changes in refraction, caused by the influence of atmospheric turbulence. The aim of this work is to study the dynamic method for determining refraction in a turbulent atmosphere. The measurements were performed with a Trimble S9 total station. It was found out, that within a few seconds the angle of vertical refraction can change by dozens of arc seconds. To improve the accuracy of the results, it is necessary to determine the refraction instantly for a specific moment of observation and for a particular path, otherwise the obtained corrections will not correspond to the real angle of refraction. The introduction of a dynamic method for determining refraction requires more extensive experimental studies under various observation conditions. In the case of confirmation of the high accuracy of the dynamic method for determining the fraction, significant prospects open up for taking refraction into account and developing new more effective measuring instruments in a turbulent atmosphere.

scholarly journals A New Method to Verify the Measurement Speed and Accuracy of Frequency Modulated Interferometers

2021 ◽  
Vol 11 (13) ◽  
pp. 5787
Author(s):  
Toan-Thang Vu ◽  
Thanh-Tung Vu ◽  
Van-Doanh Tran ◽  
Thanh-Dong Nguyen ◽  
Ngoc-Tam Bui
Keyword(s):  
Phase Change ◽  
High Speed ◽  
Measurement Accuracy ◽  
Slow Motion ◽  
New Method ◽  
Virtual Displacement ◽  
Electro Optic ◽  
Lock In ◽  
Speed And Accuracy ◽  
Electro Optic Modulator

The measurement speed and measurement accuracy of a displacement measuring interferometer are key parameters. To verify these parameters, a fast and high-accuracy motion is required. However, the displacement induced by a mechanical actuator generates disadvantageous features, such as slow motion, hysteresis, distortion, and vibration. This paper proposes a new method for a nonmechanical high-speed motion using an electro-optic modulator (EOM). The method is based on the principle that all displacement measuring interferometers measure the phase change to calculate the displacement. This means that the EOM can be used to accurately generate phase change rather than a mechanical actuator. The proposed method is then validated by placing the EOM into an arm of a frequency modulation interferometer. By using two lock-in amplifiers, the phase change in an EOM and, hence, the corresponding virtual displacement could be measured by the interferometer. The measurement showed that the system could achieve a displacement at 20 kHz, a speed of 6.08 mm/s, and a displacement noise level < 100 pm//√Hz above 2 kHz. The proposed virtual displacement can be applied to determine both the measurement speed and accuracy of displacement measuring interferometers, such as homodyne interferometers, heterodyne interferometers, and frequency modulated interferometers.

scholarly journals Analysis of depth-sensing indentation tests with a Knoop indenter

2001 ◽  
Vol 16 (6) ◽  
pp. 1660-1667 ◽  
Author(s):  
L. Riester ◽  
T. J. Bell ◽  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Elastic Recovery ◽  
Indentation Test ◽  
New Method ◽  
Short Axis ◽  
Depth Sensing ◽  
Specimen Material ◽  
Indentation Tests ◽  
Conventional Methods ◽  
Knoop Indenter

The present work shows how data obtained in a depth-sensing indentation test using a Knoop indenter may be analyzed to provide elastic modulus and hardness of the specimen material. The method takes into account the elastic recovery along the direction of the short axis of the residual impression as the indenter is removed. If elastic recovery is not accounted for, the elastic modulus and hardness are overestimated by an amount that depends on the ratio of E/H of the specimen material. The new method of analysis expresses the elastic recovery of the short diagonal of the residual impression into an equivalent face angle for one side of the Knoop indenter. Conventional methods of analysis using this corrected angle provide results for modulus and hardness that are consistent with those obtained with other types of indenters.

scholarly journals A new method using a vessel-sealing system provides coagulation effects to various types of bleeding with less thermal damage

2020 ◽  
Author(s):  
Shosaburo Oyama ◽  
Takashi Nonaka ◽  
Keitaro Matsumoto ◽  
Daisuke Taniguchi ◽  
Yasumasa Hashimoto ◽  
...  
Keyword(s):  
Small Intestine ◽  
Thermal Damage ◽  
New Method ◽  
Porcine Liver ◽  
Energy Devices ◽  
Vessel Sealing System ◽  
Vessel Sealing ◽  
Soft Coagulation ◽  
Conventional Methods ◽  
Porcine Organs

Abstract Background Hemostasis is very important for a safe surgery, particularly in endoscopic surgery. Accordingly, in the last decade, vessel-sealing systems became popular as hemostatic devices. However, their use is limited due to thermal damage to organs, such as intestines and nerves. We developed a new method for safe coagulation using a vessel-sealing system, termed flat coagulation (FC). This study aimed to evaluate the efficacy of this new FC method compared to conventional coagulation methods. Methods We evaluated the thermal damage caused by various energy devices, such as the vessel-sealing system (FC method using LigaSure™), ultrasonic scissors (Sonicision™), and monopolar electrosurgery (cut/coagulation/spray/soft coagulation (SC) mode), on porcine organs, including the small intestine and liver. Furthermore, we compared the hemostasis time between the FC method and conventional methods in the superficial bleeding model using porcine mesentery. Results FC caused less thermal damage than monopolar electrosurgery’s SC mode in the porcine liver and small intestine (liver: mean depth of thermal damage, 1.91 ± 0.35 vs 3.37 ± 0.28 mm; p = 0.0015). In the superficial bleeding model, the hemostasis time of FC was significantly shorter than that of electrosurgery’s SC mode (mean, 19.54 ± 22.51 s vs 44.99 ± 21.18 s; p = 0.0046). Conclusion This study showed that the FC method caused less thermal damage to porcine small intestine and liver than conventional methods. This FC method could provide easier and faster coagulation of superficial bleeds compared to that achieved by electrosurgery’s SC mode. Therefore, this study motivates for the use of this new method to achieve hemostasis with various types of bleeds involving internal organs during endoscopic surgeries.

A Model for Non-Invasive Estimation of in Vivo Dialyzer Performances and Patient's Conductivity during Hemodialysis

1993 ◽  
Vol 16 (8) ◽  
pp. 585-591 ◽  
Author(s):  
T. Petitclerc ◽  
N. Goux ◽  
A.L. Reynier ◽  
B. Béné
Keyword(s):  
Strong Correlation ◽  
New Method ◽  
Conductivity Measurements ◽  
Urea Clearance ◽  
Non Invasive ◽  
Model Based ◽  
On Line ◽  
Conventional Methods

On-line monitoring of hemodialysis sessions requires a non-invasive estimation of the parameters concerning the patient's status and the dialyzer performances. We describe here a model based on a new method for non-invasive dialysance and patient conductivity measurements. In this technique the same probe measures alternately the conductivity at the dialysate inlet and outlet for two different dialysate conductivity values. From these data, an appropriate model allows to determine the patient's conductivity as well as the effective dialysance of ionised solutes, that is to say the dialysance corrected for recirculation. A strong correlation is evidenced between the effective dialysance measured by this method and the urea clearance measured by conventional methods (r=0.98 for in vitro solutions; r=0.82 in in vivo situations).

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