scholarly journals Galilei was Wrong: Angular Nonradial Effects of Radial Gravity Depend on Density of Matter

2014 ◽  
Vol 30 ◽  
pp. 89-105
Author(s):  
Jakub Czajko
Keyword(s):  
Gravitational Force ◽  
Internal Validity ◽  
Equipotential Surface ◽  
Large Mass ◽  
Radio Waves ◽  
Mass Source ◽  
Gravity Center ◽  
Actual Meaning ◽  
Equipotential Surfaces ◽  
The Impact

Although in mathematical sense the actual meaning of Galilei's experiments conducted at leaning tower of Pisa is that he failed to detect any measurable impact of composition of matter on gravitating bodies, the obvious failure is mistakenly interpreted as experimental confirmation of lack of the impact instead. Galilei did not really perform internal validity checks of his experiments, because he did not ensure that he actually measured what he was supposed to measure. However, a modern experiment devised to test the impact of large mass on gravitational phenomena has revealed presence of (formerly unanticipated) extraneous frequency decrease in rays coming from Taurus A, when they passed close to our Sun (i.e. near occultation). The experiment has effectively confirmed that density of matter of the mass source of locally dominant gravitational field (which was our Sun‟s field) affects gravitational interactions happening on equipotential surfaces surrounding gravity center of the field. Also very similar experiment involving radio waves, which too exhibited (formerly unexpected) frequency decrease when they traveled along practically equipotential surface of Earth, has reaffirmed that conclusion. Hence contrary to Galilei, effects of nonradial (i.e. tangential and/or binormal) components of radial gravitational force fields depend (inversely) on (equipotential exposure to) the, assumed as practically constant and uniformly distributed, density of matter of the mass source of the local field.

Impact of Different Film-Cooling Modes at Trailing Edge on the Aerodynamic Performance of Heavy Duty Gas Turbine Cascade

2011 ◽  
Vol 84-85 ◽  
pp. 259-263
Author(s):  
Xun Liu ◽  
Song Tao Wang ◽  
Xun Zhou ◽  
Guo Tai Feng
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Large Mass ◽  
Turbine Cascade ◽  
Heavy Duty ◽  
Trailing Edge ◽  
Central Difference ◽  
Adiabatic Effectiveness ◽  
Heavy Duty Gas Turbine ◽  
The Impact

In this paper, the trailing edge film cooling flow field of a heavy duty gas turbine cascade has been studied by central difference scheme and multi-block grid technique. The research is based on the three-dimensional N-S equation solver. By way of analysis of the temperature field, the distribution of profile pressure, and the distribution of film-cooling adiabatic effectiveness in the region of trailing edge with different cool air injection mass and different angles, it is found that the impact on the film-cooling adiabatic effectiveness is slightly by changing the injection mass. The distribution of profile pressure dropped intensely at the pressure side near the injection holes line with the large mass cooling air. The cooling effect is good in the region of trailing edge while the injection air is along the direction of stream.

Design and analysis of a segmented blade for a 50 MW wind turbine rotor

2022 ◽  
pp. 0309524X2110693
Author(s):  
Alejandra S Escalera Mendoza ◽  
Shulong Yao ◽  
Mayank Chetan ◽  
Daniel Todd Griffith
Keyword(s):  
Wind Turbine ◽  
Large Mass ◽  
Turbine Rotor ◽  
Bolted Joints ◽  
Bonded Joints ◽  
Sheer Size ◽  
Extreme Scale ◽  
The Impact ◽  
Adhesive Materials ◽  
Wind Turbine Rotor

Extreme-size wind turbines face logistical challenges due to their sheer size. A solution, segmentation, is examined for an extreme-scale 50 MW wind turbine with 250 m blades using a systematic approach. Segmentation poses challenges regarding minimizing joint mass, transferring loads between segments and logistics. We investigate the feasibility of segmenting a 250 m blade by developing design methods and analyzing the impact of segmentation on the blade mass and blade frequencies. This investigation considers various variables such as joint types (bolted and bonded), adhesive materials, joint locations, number of joints and taper ratios (ply dropping). Segmentation increases blade mass by 4.1%–62% with bolted joints and by 0.4%–3.6% with bonded joints for taper ratios up to 1:10. Cases with large mass growth significantly reduce blade frequencies potentially challenging the control design. We show that segmentation of an extreme-scale blade is possible but mass reduction is necessary to improve its feasibility.

The impact of hedonic dining experiences on word of mouth, switching intentions and willingness to pay

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anupama Sukhu ◽  
Anil Bilgihan
Keyword(s):  
Willingness To Pay ◽  
Word Of Mouth ◽  
Internal Validity ◽  
Service Encounters ◽  
Student Sample ◽  
Content Type ◽  
Hedonic Value ◽  
Restaurant Managers ◽  
Positive Word Of Mouth ◽  
The Impact

PurposeWhen customers decide to dine out, they choose a restaurant for both physiological and psychological reasons. The psychological reasons include the hedonic/enjoyment goal of the consumer. The purpose of this paper is to investigate whether dining experiences that provide a positive or negative hedonic value will influence positive word of mouth (PWOM), switching intentions (SI) and willingness to pay (WTP).Design/methodology/approachTwo survey-based experiments using student (N = 112) and general restaurant consumer samples (N = 270) were conducted to test the proposed theoretical model. The student sample provided internal validity, whereas the general consumer sample provided external validity for the study. Two types of manipulations were used to manipulate positive and negative restaurant service encounters. The second study randomly assigned participants into positive or negative scenarios.FindingsThe results suggest that positive (negative) service encounters lead to higher (lower) hedonic value. Higher hedonic value leads to PWOM, WTP and reduced SI. The findings of this study would assist restaurant managers and service scholars by bridging the gap between experiential and relationship marketing.Originality/valueThe current research investigates the dining out experience with a holistic lens.

VP08 Real-World Data Use In Health Technology Assessments: A Comparison Of Five Health Technology Assessment Agencies

2017 ◽  
Vol 33 (S1) ◽  
pp. 149-150
Author(s):  
Amr Makady ◽  
Ard van Veelen ◽  
Anthonius de Boer ◽  
Hans Hillege ◽  
Olaf Klunger ◽  
...  
Keyword(s):  
Health Technology Assessment ◽  
Technology Assessment ◽  
Real World ◽  
Relative Effectiveness ◽  
Internal Validity ◽  
Health Technology ◽  
Real World Data ◽  
World Data ◽  
The Impact

INTRODUCTION:Reimbursement decisions are usually based on evidence from randomized controlled trials (RCT) with high internal validity but lower external validity. Real-World Data (RWD) may provide complimentary evidence for relative effectiveness assessments (REA's) and cost-effectiveness assessments (CEA's) of treatments. This study explores to which extent RWD is incorporated in REA's and CEA's of drugs used to treat metastatic melanoma (MM) by five Health Technology Assessment (HTA) agencies.METHODS:Dossiers for MM drugs published between 1 January 2011 and 31 December 2016 were retrieved for HTA agencies in five countries: the United Kingdom (NICE), Scotland (SMC), France (HAS), Germany (IQWiG) and the Netherlands (ZIN). A standardized data-extraction form was used to extract data on RWD mentioned in the assessment and its impact on appraisal (for example, positive, negative, neutral or unknown) for both REA and CEA.RESULTS:In total, fourty-nine dossiers were retrieved: NICE = 10, SMC = 13, IQWiG = 16, HAS = 8 and ZIN = 2. Nine dossiers (18.4 percent) included RWD in REA's for several parameters: to describe effectiveness (n = 5) and/or the safety (n = 2) of the drug, and/or the prevalence of MM (n = 4). CEA's were included in 25/49 dossiers (IQWiG and HAS did not perform CEA's). Of the twenty-five CEA's, twenty (80 percent) included RWD to extrapolate long-term effectiveness (n = 19), and/or identify costs associated with treatments (n = 7). When RWD was included in REA's (n = 9), its impact on the appraisal was negative (n = 4), neutral (n = 2), unknown (n = 1) or was not discussed in the appraisal (n = 2). When RWD was included in CEA's (n = 11), its impact on the appraisal varied between positive (n = 2), negative (n = 5) and unknown (n = 4).CONCLUSIONS:Generally, RWD is more often included in CEA's than REA's (80 percent versus 18.4 percent, respectively). When included, RWD was mostly used to describe the effectiveness of the drug (REA) or to predict long-term effectiveness (CEA). The impact of RWD on the appraisal varied greatly within both REA's and CEA's.

scholarly journals Time-Frequency Characteristics of In-Home Radio Channels Influenced by Activities of the Home Occupant

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3557
Author(s):  
Alireza Borhani ◽  
Matthias Pätzold ◽  
Kun Yang
Keyword(s):  
Radio Channel ◽  
Wearable Sensors ◽  
Fall Detection ◽  
The Body ◽  
Home Healthcare ◽  
Radio Waves ◽  
Time Frequency ◽  
Daily Life Activities ◽  
Data Files ◽  
The Impact

While aging is a serious global concern, in-home healthcare monitoring solutions are limited to context-aware systems and wearable sensors, which may easily be forgotten or ignored for privacy and comfort reasons. An emerging non-wearable fall detection approach is based on processing radio waves reflected off the body, who has no active interaction with the system. This paper reports on an indoor radio channel measurement campaign at 5.9 GHz, which has been conducted to study the impact of fall incidents and some daily life activities on the temporal and spectral properties of the indoor channel under both line-of-sight (LOS) and obstructed-LOS (OLOS) propagation conditions. The time-frequency characteristic of the channel has been thoroughly investigated by spectrogram analysis. Studying the instantaneous Doppler characteristics shows that the Doppler spread ignores small variations of the channel (especially under OLOS conditions), but highlights coarse ones caused by falls. The channel properties studied in this paper can be considered to be new useful metrics for the design of reliable fall detection algorithms. We share all measured data files with the community through Code Ocean. The data can be used for validating a new class of channel models aiming at the design of smart activity recognition systems via a software-based approach.

scholarly journals LO17: Examining publication bias among randomized controlled trials in child health research: a follow-up study

CJEM ◽  
2018 ◽  
Vol 20 (S1) ◽  
pp. S12-S12 ◽  
Author(s):  
L. K. Crockett ◽  
T. Klassen
Keyword(s):  
Child Health ◽  
Publication Bias ◽  
Editorial Policy ◽  
Rank Correlation ◽  
Internal Validity ◽  
Risk Of Bias ◽  
Phase Iii ◽  
Publication Rates ◽  
The Impact ◽  
Over Time

Introduction: Non-publication of trial findings results in research waste and compromises medical evidence and the safety of interventions in child health. The objectives of this study were to replicate, compare and contrast findings of a previous study (Klassen et al., 2002) to determine the impact of ethical and editorial mandates to register and publish findings. Methods: Abstracts accepted to the Pediatric Academic Societies meetings (2008-2011) were screened in duplicate to identify Phase-III RCTs enrolling pediatric populations. Subsequent publication was ascertained through a search of electronic databases. Study internal validity was measured using Cochrane Risk of Bias and Jadad Scale, and key variables (e.g., trial design, study stage) were extracted. Pearson X2, t-tests and Wilcoxon rank sum tests were used to examine association between variables and publication status. Logistic regression, log-rank tests, rank correlation and Egger regression were used to assess predictors of publication, time to publication and publication bias, respectively. Results: Compared to our previous study, fewer studies remained unpublished (27.9% vs 40.9%, p=.007). Abstracts with higher sample sizes (p=0.01) and those registered in ClinicalTrials.gov were more likely to be published (p<.0001). There were no differences in quality measures/risk of bias or in preference for positive results (p=0.36) between published and unpublished studies. Mean time to publication was 26.5 months and published manuscripts appeared most frequently in Pediatrics, the Journal of Pediatrics, and Pediatric Emergency Care. The funnel plot (p=0.04) suggests a reduced but ongoing existence of publication bias among published studies. Overall, we observed a reduction in publication bias and in preference for positive findings, and an increase in study size and publication rates over time. Conclusion: Despite heightened safeguards and editorial policy changes in recent decades, publication bias remains commonplace and presents a threat to assessing the efficacy and effectiveness of interventions in child health. Our results suggest a promising trend towards a reduction in publication bias over time and positive impacts of trial registration. Further efforts are needed to ensure the entirety of evidence can be accessed when assessing treatment effectiveness.

A novel shock isolator for heavy structure installation

2010 ◽  
Vol 224 (2) ◽  
pp. 283-292 ◽  
Author(s):  
L-J Zhang ◽  
C-M Zhu ◽  
X Shi ◽  
P Zhang
Keyword(s):  
External Disturbance ◽  
Large Mass ◽  
Peak Acceleration ◽  
Elastic Impact ◽  
Air Bags ◽  
Physical Limit ◽  
Huge Impact ◽  
The Impact ◽  
Heavy Structure ◽  
Impact Head

During the heavy structure installation process, any external disturbance may result in a huge impact on the substructure due to the extremely large mass involved, which may damage the whole structure permanently. Therefore, a reliable shock isolator for the installation interface is very important in such applications. In this study, a novel shock isolator based on a hydraulic damper is presented. It has been designed with an optimized throttling orifice to dissipate the energy efficiently and with air bags to store energy. Considering the maximal relative travel range of the isolator within a specified physical limit, the design is formulated as an optimization problem to minimize the peak acceleration during the impact and finalized as a constant force isolator. A mathematical model of the isolator is established and a prediction of its performance is obtained through some simulations. Experiments are performed to evaluate the theoretical model and it is found that the experimental data agree with the theoretical prediction very well, and thus validates the design. The influence of initial oil pressure and the material of elastic impact head are also investigated. The results show that higher initial oil pressure increases the peak acceleration, while the material of the elastic impact head has no significant effect on that.

Evaluation of the effectiveness of radio frequency (RF) treatment on improving the overall appearance of the facial skin in women – a pilot study

2020 ◽  
Vol 11 (2) ◽  
pp. 8-14
Author(s):  
Monika Wilk ◽  
Amelia Lizak ◽  
Aleksandra Matuła ◽  
Anna Ściasłowska-Czarnecka
Keyword(s):  
Visual Assessment ◽  
Skin Condition ◽  
Partial Reduction ◽  
Radio Waves ◽  
Facial Skin ◽  
Regenerative Processes ◽  
Non Invasive ◽  
Global Trend ◽  
The Face ◽  
The Impact

Introduction: Aging facial skin is a natural and unavoidable process. It involves a gradual weakening of the biological activity of cells, extension of regenerative processes and reduction of adaptability. At the same time, a smooth, radiant, wrinkle-free complexion has been a global trend in cosmetology for many years, which results in more and more people, especially women, benefiting from new non-invasive anti-aging treatments. One of such treatments offered on the cosmetology market are treatments utilising RF radio waves. Therefore, the aim of this study was to assess the impact of a series of treatments utilising RF on the skin of the faces of women. Materials and methods: The analysis of the results was carried out by the examined person and by the authors of the project via a point scale of visual assessment of skin condition. The following facial skin parameters were analysed in the study: depth of wrinkles, elasticity, skin brightening and moisturising. Results and conclusions: The conducted own study proves the impact of treatments using RF radio waves on the skin of the face. The applied series of treatments caused a partial reduction of the most visible and deepest wrinkles, as well as improved elasticity, brightening and moisturising of the facial skin.

scholarly journals Investigation on the Application of Taylor Impact Test to High-G Loading

2021 ◽  
Vol 8 ◽  
Author(s):  
Li Juncheng ◽  
Chen Gang ◽  
Lu Yonggang ◽  
Huang Fenglei
Keyword(s):  
Pulse Duration ◽  
Impact Loading ◽  
Impact Test ◽  
Impact Load ◽  
Low Cost ◽  
Large Mass ◽  
Impact Testing ◽  
Taylor Impact ◽  
Taylor Impact Test ◽  
The Impact

Taylor impact test is characterized by high impact energy, low cost, and good repeatability, giving it the technical foundation and development potential for application in high-g loading. In this paper, the feasibility of performing high-g load impact testing to a missile-borne recorder by conducting Taylor impact test was studied by combining simulation analyses with experimental verification. Acccording to the actual dimensions of the missile-borne recorder, an experimental piece was designed based on the Taylor impact principle. The impact loading characteristics of the missile-borne recorder were then simulated and analyzed at different impact velocities. In addition, the peak acceleration function and the pulse duration function of the load were fitted to guide the experimental design. A Taylor-Hopkinson impact experiment was also conducted to measure the impact load that was actually experienced by the missile-borne recorder and the results were compared with the results of strain measurements on the Hopkinson incident bar. The results showed that the peak value of impact load, the pulse duration and the waveform of the actual experimental results were in good agreement with the results predicted by the simulations. Additionally, the strain data measured on the incident bar could be used to verify or replace the acceleration testing of the specimen to simplify the experimental process required. Based on the impact velocity, high-g loading impact was achieved with peak values in the 7,000–30,000 g range and durations of 1.3–1 ms, and the waveform generated was a sawtooth wave. The research results provide a new approach for high amplitude and long pulse duration impact loading to large-mass components, and broaden the application field of Taylor impact test.

scholarly journals Low-Complexity Security Algorithm Again Black-hole Attacking Node Considering Energy Balance for WSNs

2020 ◽  
Vol 18 (4.2) ◽  
pp. 26
Author(s):  
Phat Nguyen Huu
Keyword(s):  
Black Hole ◽  
Ad Hoc ◽  
Low Complexity ◽  
Network Simulator ◽  
Radio Waves ◽  
Rest Energy ◽  
Attack Model ◽  
Wired Networks ◽  
Wide Range ◽  
The Impact

Wireless sensor network (WSN) is a network through radio waves to link a large number of unevenly distributed nodes on a wide range of areas for the purpose of sensing, processing and collecting data.The data transmitted in WSNs is usually sensitive that needs to be protected. WSNs are more vulnerable to attacks due to network characteristics such as wireless transmission, changing network topologies, computing power, limited memory and power of nodes comparing to wired networks. There are many types of attacks on WSNs such as sinkhole attacks, data integrity attacks, wormhole attacks, Black hole attacks, etc. In this article, we will evaluate the impact of Black-hole attacks in the WSN network when using the AODV routing protocol (Ad-hoc On-demand Distance Vector routing). The Black hole attack model will be simulated by Network Simulator 2 (NS-2) by the number of lost packets by counting the number of packets sent by the sending node, receiving packets to destination, and rest energy of the nodes in two cases.

Sign in / Sign up

Export Citation Format

Share Document