scholarly journals The importance of the surface roughness and running band area on the bottom of a stone for the curling phenomenon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takao Kameda ◽  
Daiki Shikano ◽  
Yasuhiro Harada ◽  
Satoshi Yanagi ◽  
Kimiteru Sado
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Theoretical Model ◽  
Surface Condition ◽  
Model Calculations ◽  
Band Area ◽  
Ice Surface ◽  
The Subject ◽  
Circular Target ◽  
Precise Experimental Data

AbstractCurling is a sport in which players deliver a cylindrical granite stone on an ice sheet in a curling hall toward a circular target located 28.35 m away. The stone gradually moves laterally, or curls, as it slides on ice. Although several papers have been published to propose a mechanism of the curling phenomenon for the last 100 years, no established theory exists on the subject, because detailed measurements on a pebbled ice surface and a curling stone sliding on ice and detailed theoretical model calculations have yet to be available. Here we show using our precise experimental data that the curl distance is primarily determined by the surface roughness and the surface area of the running band on the bottom of a stone and that the ice surface condition has smaller effects on the curl distance. We also propose a possible mechanism affecting the curling phenomena of a curing stone based on our results. We expect that our findings will form the basis of future curling theories and model calculations regarding the curling phenomenon of curling stones. Using the relation between the curl distance and the surface roughness of the running band in this study, the curl distance of a stone sliding on ice in every curling hall can be adjusted to an appropriate value by changing the surface roughness of the running band on the bottom of a stone.

scholarly journals Experimental Correlation for Splashing Condition of Droplets on Solid Substrates

Fluids ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 38
Author(s):  
Yukihiro Yonemoto ◽  
Kanta Tashiro ◽  
Minori Yamashita ◽  
Tomoaki Kunugi
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Surface Roughness ◽  
Surface Condition ◽  
Reynolds Numbers ◽  
Solid Surfaces ◽  
Ohnesorge Number ◽  
Capillary Length ◽  
Solid Substrates ◽  
Experimental Correlation

Droplet splashing behaviors of water-ethanol binary mixture liquids on roughened solid surfaces were experimentally observed in order to investigate the effects of surface tension, viscosity, and wettability/surface roughness on the splashing occurrence. The range of the droplet volumes was from 1.7 μL to 32.6 μL. The ranges of the surface tension and the viscosity were from 21.1 mN/m to 71.9 mN/m, and from 1 mPas to 2.91 mPas, respectively. The surface roughness range was from 0.03 μm to 1.25 μm for Ra. The present experimental data were evaluated on the basis of the existing models. Resulting from these experiments, a simple model using the Ohnesorge number evaluated by the capillary length was proposed and the accuracy of the predicted critical values such as the critical Weber and Reynolds numbers were discussed. The result indicated that the liquid properties and the quantification of the surface condition such as surface roughness are important factors for the prediction of the splashing behavior.

RADIATIVE M1-TRANSITIONS OF HEAVY MESONS IN LIGHT-FRONT QUARK MODEL

2008 ◽  
Vol 23 (21) ◽  
pp. 3259-3262
Author(s):  
HO-MEOYNG CHOI
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Quark Model ◽  
Radiative Decay ◽  
Light Front ◽  
Effective Hamiltonian ◽  
Model Calculations ◽  
Heavy Mesons ◽  
Decay Widths ◽  
Good Agreement

We present the magnetic dipole(M1) transitions V → Pγ of various heavy-flavored mesons such as [Formula: see text] and [Formula: see text] using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. Our numerical results for the radiative decay widths are in good agreement with the available experimental data as well as other theoretical model calculations.

A Method for Estimating Mass Transfer Coefficients in a Packed Column Using Reactive Absorption Data

2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Optimization Technique ◽  
Packed Column ◽  
Effective Area ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Model Calculations ◽  
Unit Model ◽  
Reactive Absorption

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.

Fuzzy Modeling to Simulate Surface Roughness in CNC Turning of AISI 1045 Steel

2011 ◽  
Vol 486 ◽  
pp. 262-265
Author(s):  
Amit Kohli ◽  
Mudit Sood ◽  
Anhad Singh Chawla
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Process Parameters ◽  
Fuzzy Model ◽  
Fuzzy Modeling ◽  
Cnc Machine ◽  
Model Based ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel

The objective of the present work is to simulate surface roughness in Computer Numerical Controlled (CNC) machine by Fuzzy Modeling of AISI 1045 Steel. To develop the fuzzy model; cutting depth, feed rate and speed are taken as input process parameters. The predicted results are compared with reliable set of experimental data for the validation of fuzzy model. Based upon reliable set of experimental data by Response Surface Methodology twenty fuzzy controlled rules using triangular membership function are constructed. By intelligent model based design and control of CNC process parameters, we can enhance the product quality, decrease the product cost and maintain the competitive position of steel.

Comparative Analysis between Conventional and Dry Turning

2017 ◽  
Vol 261 ◽  
pp. 267-274
Author(s):  
Pantelis N. Botsaris ◽  
Chaido Kyritsi ◽  
Dimitris Iliadis
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Cutting Tool ◽  
Spindle Motor ◽  
Air Cooling ◽  
Machining Parameters ◽  
Turning Process ◽  
Dry Cutting ◽  
Cold Air ◽  
Cooling And Lubrication

In this paper, there is an attempt to monitor and evaluate machining parameters when turning 34CrNiMo6 material under different cooling and lubrication conditions. The machining parameters concerned are temperature of the cutting tool and the workpiece, level of vibrations of the cutting tool, surface roughness of the workpiece, noise levels of the turning process and current drawn by the main spindle motor. Four different experimental machining scenarios were completed, specifically: conventional wet turning process, dry cutting and two additional modes employing cooling by cold air. Experimental data were acquired and recorded by an optimally designed network of sensors. Experimental data were statistically analyzed in order to reach conclusions. According to the research that has been done, although, overall, minimum cutting tool and workpiece temperatures were observed under wet machining, cold air cooling is capable of achieving comparable cooling results to wet machining. The lowest values of surface roughness were achieved by wet machining, whereas the lowest level of cutting tool vibrations were observed under cold air cooling.

In Reply: Combinations of Antibiotics

PEDIATRICS ◽  
1960 ◽  
Vol 26 (3) ◽  
pp. 499-499
Author(s):  
Robert J. Haggerty
Keyword(s):  
Experimental Data ◽  
Clinical Data ◽  
Experimental Work ◽  
The Subject ◽  
Antimicrobial Combinations

I am delighted to have Dr. Jawetz again bring to the attention of your readers his definitive work on the subject of antimicrobial combinations. We certainly have no quarrel with the points he reiterates. Our choice of words, "It is not clear why these results are at variance with the experimental data of Jawetz or the clinical data of Lepper and Dowling," was probably unfortunate, for Dr. Jawetz points out why the results did differ from his experimental work.

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