Combined Test of the Gravitational Inverse-Square Law at the Centimeter Range

2021 ◽  
Vol 126 (21) ◽  
Author(s):  
Jun Ke ◽  
Jie Luo ◽  
Cheng-Gang Shao ◽  
Yu-Jie Tan ◽  
Wen-Hai Tan ◽  
...  
Author(s):  
David M. Wittman

Having developed a framework for subsuming gravity into relativity, we examine how gravity behaves as a function of the source mass (Earth, Sun, etc.) and distance from that sourcemass.We develop Newton’s inverse‐square law of gravity, and we examine the consequences in terms of acceleration fields, potentials, escape velocities, and surface gravity. Chapter 17 will build on these ideas to show how orbits are used to probe gravity throughout the universe.We also develop a tool for exposing variations in the acceleration field: the tidal acceleration field in any region is defined as the acceleration field in that region minus the average acceleration. This enables us to restate Newton’s lawof gravity as: the acceleration arrows surrounding any point show a net convergence that is proportional to the density of mass at that point. Chapter 18 will use this to develop a frame‐independent law of gravity.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nichtima Chayaopas ◽  
Pornthep Kasemsiri ◽  
Panida Thanawirattananit ◽  
Patorn Piromchai ◽  
Kwanchanok Yimtae

Abstract Background Globally increasing number of elders is concerned. Hearing loss process in older adults cannot be avoided. An effective screening tool for hearing loss is essential for proper diagnosis and rehabilitation, which can improve QOL in older adults. Methods This prospective-diagnostic test study evaluates the diagnostic value of Thai version of the Hearing Handicap Inventory for Elderly Screening (HHIE-ST) and the Thai Single Question (TSQ) surveys in screening hearing disability in 1109 Thai participants aged 60 years and older in communities in four provinces in Thailand. The HHIE-ST consisted of 10 selected questions from the validated HHIE-Thai version. A TSQ survey was developed to have the same meaning as an English Single Question survey. The participants answered both questionnaires, and a standard audiometry test assessed with air conduction from 250 to 8000 Hz was included as a gold standard. Results The prevalence of hearing disability was 38.34%. The HHIE-ST achieved a sensitivity of 88.96% (95% CI 85.77–91.64) and specificity of 52.19% (95% CI 48.24–56.13) for diagnosis hearing disability in Thai older adults, whereas the TSQ yielded a sensitivity of 88.73% and a specificity of 55.93%. A combined test including the HHIE-ST and TSQ achieved better performance with sensitivity of 85.29% and specificity of 60.13%. Conclusions Either the HHIE-ST or the TSQ is a sensitive and useful tool for screening hearing disability in Thai older adults. Using the HHIE-ST together with the TSQ resulted in a better screening tool for detecting moderate hearing loss older adults who will benefit and recommended for hearing rehabilitation. Trial registration The study is registered with the following number in the Thai Clinical Trials Registry: TCTR20151015003. Date of registration October 14, 2015.


Author(s):  
Paul Ritchie ◽  
Özkan Karabacak ◽  
Jan Sieber

A classical scenario for tipping is that a dynamical system experiences a slow parameter drift across a fold tipping point, caused by a run-away positive feedback loop. We study what happens if one turns around after one has crossed the threshold. We derive a simple criterion that relates how far the parameter exceeds the tipping threshold maximally and how long the parameter stays above the threshold to avoid tipping in an inverse-square law to observable properties of the dynamical system near the fold. For the case when the dynamical system is subject to stochastic forcing we give an approximation to the probability of tipping if a parameter changing in time reverses near the tipping point. The derived approximations are valid if the parameter change in time is sufficiently slow. We demonstrate for a higher-dimensional system, a model for the Indian summer monsoon, how numerically observed escape from the equilibrium converge to our asymptotic expressions. The inverse-square law between peak of the parameter forcing and the time the parameter spends above a given threshold is also visible in the level curves of equal probability when the system is subject to random disturbances.


2014 ◽  
Vol 977 ◽  
pp. 334-337
Author(s):  
Xi Lei ◽  
Gui Zhi Xu ◽  
Ke Zheng Xing

As a flexible AC transmission system equipment, controlled shunt reactor is becoming increasingly important in the grid with the development of EHV / UHV transmission systems. Since currently rated voltage of controlled shunt reactor has developed to 1100kV, as its capacity control system, or valve-control system, stability and reliability test is very important. In this paper, the test circuit and method for the valve-control system in the laboratory or the test station for combined adjustment test is put forward. By adjustment of power supply and the device parameter, the valve-control system can put the voltage and current of the device to be the same as the on-set operation. Actual test of the world's first 1100kV controlled shunt reactor valve-control system shows that, the test method in this paper is correct and feasible, and the objective of assessment can be achieved.


2004 ◽  
Vol 13 (10) ◽  
pp. 2249-2254
Author(s):  
JASON H. STEFFEN

Many theories which unify gravity with the other known forces of nature predict the existence of an intermediate-range "fifth force" similar to gravity. Such a force could be manifest as a deviation from the gravitational inverse-square law. Currently, at distances near 10-1 m, the inverse-square law is known to be correct to about one part per thousand. I present the design of an experiment that will improve this limit by two orders of magnitude. This is accomplished by constructing a torsion pendulum and source mass apparatus that are particularly insensitive to Newtonian gravity and, simultaneously, maximally sensitive to violations of the same.


2017 ◽  
Vol 72 (11) ◽  
pp. 631-632
Author(s):  
M. Santorum ◽  
D. Wright ◽  
A. Syngelaki ◽  
N. Karagioti ◽  
K. H. Nicolaides

2021 ◽  
Vol 20 (1) ◽  
pp. 113-120
Author(s):  
N.V. Zarochentseva ◽  
◽  
L.K. Dzhidzhikhiya ◽  
V.N. Nabieva ◽  
◽  
...  

Cervical intraepithelial neoplasia (CIN) refers to precancerous changes in the cervix. After surgical treatment, a certain proportion of patients remain at risk of disease reccurence. Therefore, monitoring of patients after CIN surgery is an important and necessary part of their management tactics. Objective. Review of world literature on modern approaches to patients monitoring after using excisional methods of CIN treatment. Materials and methods. The information material includes data from scientific articles on the subject available in Pubmed and published over the past 20 years. Results. The analysis of data contained in modern literature on the frequency and risk factors for the development of reccurent CIN after excisional methods of treatment, diagnostic methods, the timing of follow-up examinations during post-operative monitoring, the main approaches to monitoring in different countries and the effectiveness of the proposed strategies for postoperative follow-up of patients after treatment was conducted. It was established that the approaches to the observation of this category of patients differ in various countries. Almost everywhere, the priority tool for monitoring of patients with CIN after treatment is a combined test, which involves a joint use of cytology and human papillomavirus tests. The main difference between countries is the timing of the first post-treatment follow-up visit. In some countries a follow-up visit is recommended within 24 months, while in others it is suggested to return to routine screening if the primary combined test is negative. Conclusion. Despite existing disagreements, the proposed post-operative monitoring strategies for CIN patients provide a fairly high percentage of “healing” and return to routine screening. Key words: human papillomavirus, monitoring, cervical cancer, cervical intraepithelial neoplasia, excisional treatment


2018 ◽  
Vol 23 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Hamid Shafaei Douk ◽  
Mahmoud Reza Aghamiri ◽  
Mahdi Ghorbani ◽  
Bagher Farhood ◽  
Mohsen Bakhshandeh ◽  
...  

1960 ◽  
Vol 64 (590) ◽  
pp. 105-106 ◽  
Author(s):  
K. I. McKenzie

If a circular plate has a concentric circular hot area, there is a critical temperature for this area at which the plate buckles. This temperature is calculated in this note for the case of a clamped plate supported in such a way that the radial stress in the cold part obeys the inverse square law.


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