scholarly journals An Adaptive Remeshing Procedure for Proximity Maneuvering Spacecraft Formations

2012 ◽  
Vol 2012 ◽  
pp. 1-14
Author(s):  
Laura Garcia-Taberner ◽  
Josep J. Masdemont
Keyword(s):  
Variational Method ◽  
Libration Point ◽  
Time Interval ◽  
Adaptive Remeshing ◽  
Local Solutions ◽  
Spacecraft Formations ◽  
Maneuvering Spacecraft

We consider a methodology to optimally obtain reconfigurations of spacecraft formations. It is based on the discretization of the time interval in subintervals (called the mesh) and the obtainment of local solutions on them as a result of a variational method. Applied to a libration point orbit scenario, in this work we focus on how to find optimal meshes using an adaptive remeshing procedure and on the determination of the parameter that governs it.

High-Performance Liquid Chromatographic Determination of Memantine in Human Urine Following Solid-Phase Extraction and Precolumn Derivatization

2013 ◽  
Vol 96 (6) ◽  
pp. 1302-1307 ◽  
Author(s):  
Karim Michail ◽  
Hoda Daabees ◽  
Youssef Beltagy ◽  
Magdy Abd Elkhalek ◽  
Mona Khamis
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Therapeutic Drug ◽  
Time Interval ◽  
Precolumn Derivatization ◽  
Uv Detector

Abstract A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol–water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25–75 h seems adequate for sampling and monitoring memantine in urine.

Orbit determination of CE-4′s relay satellite in Earth-Moon L2 libration point orbit

2019 ◽  
Vol 64 (11) ◽  
pp. 2345-2355
Author(s):  
Jianfeng Duan ◽  
Zhaokui Wang
Keyword(s):  
Orbit Determination ◽  
Libration Point

scholarly journals Improved determination of hadron matrix elements using the variational method

2016 ◽  
Author(s):  
Jack Dragos ◽  
Roger Horsley ◽  
Waseem Kamleh ◽  
Derek Leinweber ◽  
Yoshifumi Nakamura ◽  
...  
Keyword(s):  
Variational Method ◽  
Matrix Elements

scholarly journals DETERMINATION OF THE PHASE FOR NUCLEON-NUCLEON SCATTERING BY HULTHEN'S VARIATIONAL METHOD

1951 ◽  
Vol 8 (2) ◽  
pp. 150
Author(s):  
H. W. PENG ◽  
HUANG TZU-CHIA
Keyword(s):  
Variational Method ◽  
Nucleon Nucleon ◽  
Nucleon Scattering

Lack of Agreement of Tympanic Membrane Temperature Assessments With Conventional Methods in a Private Practice Setting

PEDIATRICS ◽  
1992 ◽  
Vol 89 (3) ◽  
pp. 384-386
Author(s):  
Gary L. Freed ◽  
J. Kennard Fraley
Keyword(s):  
Regression Analysis ◽  
Tympanic Membrane ◽  
Otitis Media ◽  
Time Interval ◽  
Limits Of Agreement ◽  
Temperature Determination ◽  
Conventional Methods ◽  
Clinical Instrument ◽  
Lower Limits

An infrared tympanic membrane thermometer (FIRST temp) said to approximate core temperature accurately is being marketed as a noninvasive, quick, and easy-to-use clinical instrument. The determination of tympanic membrane temperatures by this device was compared with the determination of oral, rectal, or axillary temperatures by a conventional glass thermometer. Subjects were patients of a pediatric group practice in Houston, Texas. FIRST temp and conventional temperature determinations on individual patients were completed within 5 minutes of each other. The presence or absence of otitis media was noted by the examining physician. Agreement between the two methods of temperature determination was assessed by calculating limits of agreement within which 95% (±2 standard deviations) of individual differences would fall. The location of conventional thermometer (oral, rectal, axillary), time interval between the two separate measures, and the presence or absence of otitis media were entered into a multiple regression analysis to determine whether these factors influenced the observed differences between the two methods. A total of 144 patients were enrolled in the study; oral comparisons were obtained in 92 (57%) patients, rectal in 35 (24%), and axillary in 29 (19%). The upper and lower limits of agreement between temperature methods were 1.12°C and 0.89°C and the mean difference was –0.12°C. Regression analysis revealed that only the site of conventional thermometer location (oral, rectal, axillary) was a significant predictor of FIRST temp/conventional differences. Each site had a range of agreement greater than 1.65°C; axillary temperatures had the greatest range (–0.94°C to +1.30°C). Although ease and time reduction with use are attractive properties of the FIRST temp device, these data show that it is unreliable compared with conventional methods of temperature determination.

Identification of Forces in Vibrating Plates by Pointwise and Line Observations: Uniqueness and Stability

1995 ◽  
Author(s):  
Masahiro Yamamoto
Keyword(s):  
Finite Time ◽  
Large Time ◽  
Single Point ◽  
Time Interval ◽  
Finite Time Interval ◽  
Line Parallel ◽  
Vibrating Plates ◽  
External Forces ◽  
Spatially Varying

Abstract We consider determination of spatially varying external forces in a rectangle vibrating plate from displacement observed along a line parallel to a side of the plate over a finite time interval. For a suitable choice of the line and a sufficient large time interval, we prove the uniqueness of external forces and estimate them by appropriate norm of displacement. Moreover we discuss determination of external forces from displacement observed at a single point over a time interval.

Determination of the optimal mode of operation of the small thrust motors of a maneuvering spacecraft

1998 ◽  
Vol 9 (3) ◽  
pp. 237-243
Author(s):  
V. I. Bimatov ◽  
I. A. Druzhinin ◽  
I. V. Druzhinina ◽  
E. E. Libin ◽  
S. V. Chakhlov
Keyword(s):  
Mode Of Operation ◽  
Optimal Mode ◽  
Maneuvering Spacecraft

scholarly journals Determination of Resonance terms using Optical Observations of Two Meteosat Satellites

1997 ◽  
Vol 165 ◽  
pp. 355-360
Author(s):  
U. Hugentobler ◽  
T. Schildknecht ◽  
G. Beutler
Keyword(s):  
Radiation Pressure ◽  
Ccd Camera ◽  
Least Square ◽  
Optical Observations ◽  
Laser Ranging ◽  
Time Interval ◽  
Orbital Parameters ◽  
Adjustment Procedure ◽  
Relative Errors

AbstractDuring an observation campaign in winter 94/95 astrometric positions from Meteosat 4 and 5 were acquired at the Zimmerwald observatory using a CCD camera mounted in the prime focus of the 0.5 m Satellite Laser Ranging telescope. The measurements cover a time interval of four months, their precision is of the order of .The modeling of radiation pressure for the small, cylindrically shaped satellites is relatively easy and they are therefore excellent objects to probe the geopotential. The orbital parameters and the radiation pressure coefficients for the two satellites as well as the resonant coefficients C22, S22 of the geopotential were determined by a single least square adjustment procedure including all the Zimmerwald observations. The relative errors estimated for the terms C22 and S22 are of the order of 1 ÷ 3 · 10−4.

scholarly journals Determination of Critically Objects of Electric Power Systems from the Position of Energy Security

2018 ◽  
Vol 58 ◽  
pp. 03009 ◽  
Author(s):  
Dmitry Krupenev
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Energy Security ◽  
Electric Power Systems ◽  
Time Interval ◽  
Factors Affecting ◽  
Interconnected Power System ◽  
The Given

The paper deal the problem of definition and ranking of critical objects (CO) in electric power systems (EPS). The identification of the CO is necessary for the timely adoption of measures to organize the provision of the required level of energy security of the region where the object is location. The adequacy model is used for determine the critical objects of EPS, within the framework of which the simulation of the functioning of EPS during the given time interval is carried out, taking into account the main random factors affecting its operation. Approbation of the proposed approach is presented on the interconnected power system.

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