scholarly journals Capillary transport in paper porous materials at low saturation levels: normal, fast or superfast?

2020 ◽  
Vol 476 (2244) ◽  
pp. 20200488
Author(s):  
Alex V. Lukyanov ◽  
Vladimir V. Mitkin ◽  
Tristan Pryer ◽  
Penpark Sirimark ◽  
Theo G. Theofanous
Keyword(s):  
Porous Materials ◽  
Diffusion Model ◽  
Field Measurements ◽  
Capillary Transport ◽  
Liquid Saturation ◽  
Term Evolution ◽  
Low Levels ◽  
The Mathematical Model ◽  
Theoretical Results

The problem of capillary transport in fibrous porous materials at low levels of liquid saturation has been addressed. It has been demonstrated that the process of liquid spreading in this type of porous material at low saturation can be described macroscopically by a similar super-fast, nonlinear diffusion model to that which had been previously identified in experiments and simulations in particulate porous media. The macroscopic diffusion model has been underpinned by simulations using a microscopic network model. The theoretical results have been qualitatively compared with available experimental observations within the witness card technique using persistent liquids. The long-term evolution of the wetting spots was found to be truly universal and fully in line with the mathematical model developed. The result has important repercussions for the witness card technique used in field measurements of the dissemination of various low-volatility agents in imposing severe restrictions on collection and measurement times.

scholarly journals High Speed Mobility Management Performance in a Real LTE Scenario

2020 ◽  
Vol 10 (1) ◽  
pp. 5175-5179
Author(s):  
A. A. M. K. Abuelgasim ◽  
K. M. Yusof
Keyword(s):  
High Risk ◽  
Mobility Management ◽  
High Speed ◽  
Field Measurements ◽  
Mobile Operator ◽  
Seamless Connectivity ◽  
Term Evolution ◽  
Network Technologies

This paper discusses the mobility management for high-speed users, which is a crucial challenge for all mobile operators, especially when users are moving vertically across different network technologies. Mobility, also known as seamless connectivity, is directly influencing the quality of service (QoS). Mobility management-Handover (HO) performance was evaluated by field measurements of a Long Term Evolution (LTE) network of a mobile operator in the Middle East. Drive test measurements were used to analyze the results of different high-speed scenarios. User Equipment (UE) with high speed of 80-140km/h causes a high risk of failure of seamless connectivity as the HO procedure timing is longer than for UE with smaller speed. HO failure and call drop may occur when UE is moving with high speed across two adjacent cells in highways. During measurements, HO failure occurred when UE speed was 140km/h, and HO preparation timing increased when UE speed increased.

scholarly journals Description of Coastal Profile Long Term Evolution by Diffusion Model

2018 ◽  
Vol 16 (4) ◽  
pp. 13-19
Author(s):  
D. A. Baramiya ◽  
◽  
N. I. Gorbenko ◽  
M. M. Lavrentiev ◽  
◽  
...  
Keyword(s):  
Diffusion Model ◽  
Long Term Evolution ◽  
Term Evolution ◽  
Coastal Profile

Investigation of Deformation of Rock Samples

2017 ◽  
Vol 744 ◽  
pp. 61-65
Author(s):  
Mikhail Guzev ◽  
Vladimir Makarov
Keyword(s):  
Specific Volume ◽  
Mathematical Methods ◽  
Short Term ◽  
Volume Deformation ◽  
Middle Term ◽  
Rock Samples ◽  
The Mathematical Model ◽  
Theoretical Results ◽  
Good Coincidence

Deformation of rock samples compressed up to failure has been studied in laboratory. A system of trustworthy deformational precursors of the failure stage has been developed. The system includes long-term, middle-term and short-term precursors, which correspond to the threshold of dilatancy, change of the specific volume deformation, and jump of the specific volume deformation increments, respectively. Proposed methods of the complex research include deformation and mathematical methods. The mathematical model of deformation in samples of rocks at uniaxial compression is founded on hypothesis of self-equilibrium stresses. The model had been successfully used for description of oscillating deformation. Good coincidence between the experimental and theoretical results has been observed.

Long-Term Evolution of SCD-1 Satellite Temperatures Based on Comparative Analysis of Telemetric Data Measured in Orbit

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Andreia F. S. Genaro ◽  
Ezio C. Garcia ◽  
Issamu Muraoka ◽  
Kevin E. de Conde
Keyword(s):  
Mathematical Model ◽  
Thermal Behavior ◽  
Heat Dissipation ◽  
Solar Spectrum ◽  
Temperature Sensitive ◽  
Term Evolution ◽  
Optimization Routine ◽  
Experimental Values ◽  
The Mathematical Model

This paper presents results of the research investigation regarding the causes for temperature variation of the SCD-1 (data-collection satellite) by analyzing its thermal behavior evolution throughout 13 years in orbit. SCD-1, the first satellite designed and built in Brazil, was launched in 1993 and is still in operation. A mathematical model has been developed to simulate thermal behavior of SCD-1 in orbit, which was used as a working tool during project design phase, and is presented here. Temperatures of SCD-1 in orbit have been monitored and recorded in the Control and Tracking Center (São José dos Campos, SP, Brazil) since its launch. An analysis carried out at the mission’s beginning showed that all the temperatures were within the ranges predicted in model. Over the years, the battery, which is the most temperature-sensitive equipment in the satellite, had an increase in temperature approaching upper limit. A method has been developed to investigate the causes of this upswing in which an optimization routine linked to the mathematical model corrects a selected set of parameters in order to adjust the theoretical temperature values to the experimental values. By means of this methodology, data from SCD-1 were analyzed from 1995 to 2005 period and it was concluded that the rise in temperature was caused by an increase in internal battery heat dissipation and absorptivity in solar spectrum of some of the external satellite shielding, both consequences of a long-term degradation.

The long term evolution of Atens and Apollos

1999 ◽  
Vol 173 ◽  
pp. 59-74 ◽  
Author(s):  
R. Dvorak
Keyword(s):  
Long Term Evolution ◽  
Dynamical Structure ◽  
Time Intervals ◽  
Interesting Point ◽  
The Earth ◽  
Term Evolution ◽  
Numerical Integrations ◽  
Near Earth Asteroids ◽  
Theoretical Results

AbstractIn this review we report on the investigations of the long term dynamics of the Near Earth Asteroids (NEAs). In the first part some theoretical results concerning the dynamical structure of the NEA belt are explained. We then present our knowledge of the long term evolution of the orbits of NEAs for time intervals up to several million years which were derived by extensive numerical integrations. An interesting point of investigation is the steady flux from the Atens to the Apollos and vice-versa which is caused primarily by close encounters with the Earth and Venus. We also report the results concerning the probability of collisions of the NEAs with these planets. Finally the possible capture of such objects into Trojan-like orbits − thus moving in a 1:1 resonance with one of the inner planets − is discussed.

scholarly journals Matched Filter Based Spectrum Sensing Technique for 4G Cellular Network

2019 ◽  
Vol 38 (4) ◽  
pp. 973-978
Author(s):  
Shadab Kalhoro ◽  
Fahim Aziz Umrani ◽  
Mustahsan Khanzada ◽  
Liaquat Ali Rahoo
Keyword(s):  
Spectrum Sensing ◽  
Multiple Access ◽  
Matched Filter ◽  
Research Work ◽  
Energy Detection ◽  
Secondary Users ◽  
Single Carrier ◽  
Term Evolution ◽  
Theoretical Results

Modern and fast developments of wireless technologies have directed to a great demand for resources. It can be seen in the study that the range of existing spectrum is not used effectively, therefore the frequency band should be observed to ensure proper usage and to have the information of primary or licensed user is very much essential. In this research work uplink of LTE (Long-Term Evolution) is observed through MF (Matched Filter) spectrum sensing technique of CR (Cognitive Radio) network. This method examines the existence of signals in minimum possible time, reduces the hindrances between secondary users, increases accurateness of sensing and provides finest choice of threshold. In Uplink the System model which is used is known as SC-FDMA (Single Carrier Frequency Division Multiple Access). Entire simulation/results are prepared in MATLAB environment. This study also provides graphical contrast of simulated and theoretical results of matched filter and energy detection technique.

scholarly journals In-flight calibration of double-probe electric field measurements on Cluster

2014 ◽  
Vol 3 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Y. V. Khotyaintsev ◽  
P.-A. Lindqvist ◽  
C. M. Cully ◽  
A. I. Eriksson ◽  
M. André
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurements ◽  
Calibration Procedure ◽  
Double Probe ◽  
Term Evolution ◽  
Electric Field Measurements ◽  
Electric Field Instrument

Abstract. Double-probe electric field instrument with long wire booms is one of the most popular techniques for in situ measurement of electric fields in plasmas on spinning spacecraft platforms, which have been employed on a large number of space missions. Here we present an overview of the calibration procedure used for the Electric Field and Wave (EFW) instrument on Cluster, which involves spin fits of the data and correction of several offsets. We also describe the procedure for the offset determination and present results for the long-term evolution of the offsets.

Reply by Les P. Beard to José Arce

Geophysics ◽  
1996 ◽  
Vol 61 (4) ◽  
pp. 1229-1229
Author(s):  
Les P. Beard
Keyword(s):  
Mathematical Model ◽  
Case History ◽  
Theoretical Study ◽  
Single Case ◽  
Field Measurements ◽  
Field Observations ◽  
Geological Complexity ◽  
The Mathematical Model ◽  
Theoretical Results

Jose Arce is correct in his observation that the field results of Roy and Jain (1973) are in contradiction the synthetically derived results of Beard and Tripp. I agree that field observations must ultimately take precedence over synthetic results. If careful field measurements consistently contradict theoretical results, then the mathematical model must be regarded as inadequate. However, geological complexity makes a single case history no more convincing than a single theoretical study, and few in‐field IP array comparisons have been published.

scholarly journals Adaptive algorithm for mobile user positioning based on environment estimation

2014 ◽  
Vol 11 (3) ◽  
pp. 465-476
Author(s):  
Darko Grujovic ◽  
Mirjana Simic
Keyword(s):  
Mobile Communications ◽  
Low Cost ◽  
Field Measurements ◽  
Mobile User ◽  
Strength Parameter ◽  
Mobile Telecommunication ◽  
Telecommunication Systems ◽  
Term Evolution ◽  
Positioning Method

This paper analyzes the challenges to realize an infrastructure independent and a low-cost positioning method in cellular networks based on RSS (Received Signal Strength) parameter, auxiliary timing parameter and environment estimation. The proposed algorithm has been evaluated using field measurements collected from GSM (Global System for Mobile Communications) network, but it is technology independent and can be applied in UMTS (Universal Mobile Telecommunication Systems) and LTE (Long-Term Evolution) networks, also.

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