Calculation Model of Frictional Surface Temperature Rise Based on Fractal Theory

2015 ◽  
Vol 12 (15) ◽  
pp. 5799-5805
Author(s):  
Wei Wu
Keyword(s):  
Surface Temperature ◽  
Temperature Rise ◽  
Fractal Theory ◽  
Calculation Model ◽  
Frictional Surface

scholarly journals Development of Back-calculation Model for Aggregate Gradation Determination Using Fractal Theory

2018 ◽  
Vol 159 ◽  
pp. 01006
Author(s):  
Bagus Hario Setiadji ◽  
Supriyono ◽  
Djoko Purwanto
Keyword(s):  
Fractal Dimension ◽  
Fractal Theory ◽  
Asphalt Mixture ◽  
Fractal Dimensions ◽  
Calculation Model ◽  
Careful Consideration ◽  
Upper And Lower Bounds ◽  
Aggregate Gradation ◽  
Fractal Characteristic ◽  
Fractal Characteristics

Several studies have shown that fractal theory can be used to analyze the morphology of aggregate materials in designing the gradation. However, the question arises whether a fractal dimension can actually represent a single aggregate gradation. This study, which is a part of a grand research to determine aggregate gradation based on known asphalt mixture specifications, is performed to clarify the aforementioned question. To do so, two steps of methodology were proposed in this study, that is, step 1 is to determine the fractal characteristics using 3 aggregate gradations (i.e. gradations near upper and lower bounds, and middle gradation); and step 2 is to back-calculate aggregate gradation based on fractal characteristics obtained using 2 scenarios, one-and multi-fractal dimension scenarios. The results of this study indicate that the multi-fractal dimension scenario provides a better prediction of aggregate gradation due to the ability of this scenario to better represent the shape of the original aggregate gradation. However, careful consideration must be observed when using more than two fractal dimensions in predicting aggregate gradation as it will increase the difficulty in developing the fractal characteristic equations.

scholarly journals Design of floating photovoltaic system for fish pond lighting

2021 ◽  
Vol 926 (1) ◽  
pp. 012005
Author(s):  
G S H Arimufti ◽  
W Sunanda ◽  
R F Gusa
Keyword(s):  
Surface Temperature ◽  
Water Temperature ◽  
Temperature Rise ◽  
Solar Irradiance ◽  
Output Voltage ◽  
Pond Water ◽  
Photovoltaic System ◽  
Fish Pond ◽  
Photovoltaic Panel

Abstract The floating photovoltaic panel is increasingly being used. This is one of the ways to reduce temperature rise in photovoltaic panel. The floating photovoltaic panel is used for lighting at the fish pond. A unit of 8-watt lamp for lighting supplied by 1 unit of 50 Wp photovoltaic panel and 1 unit of 12 V/3.5 Ah battery. The heatsink attached to the bottom of the floating photovoltaic panel transfers heat from the panel to the fish pond water. Sensors are connected to Arduino to measure photovoltaic panel output voltage and current, solar irradiance, photovoltaic panel temperature and fish pond water temperature. From the measurement, the voltage generated from the floating photovoltaic panel is 12.71 – 14.71 V and the current is 0.15 - 1.17 A. While the solar irradiance value is 71 W/m2 to 396 W/m2, the surface temperature of photovoltaic panel is 26.9°C - 32.4°C and fish pond water temperature is 27.1°C - 30.2°C.

scholarly journals Estimates of climate system properties incorporating recent climate change

2018 ◽  
Vol 4 (1/2) ◽  
pp. 19-36 ◽  
Author(s):  
Alex G. Libardoni ◽  
Chris E. Forest ◽  
Andrei P. Sokolov ◽  
Erwan Monier
Keyword(s):  
Climate Change ◽  
Surface Temperature ◽  
21St Century ◽  
Climate Sensitivity ◽  
Temperature Rise ◽  
Heat Content ◽  
Climate System ◽  
Model Parameters ◽  
Aerosol Forcing ◽  
Global Mean

Abstract. Historical time series of surface temperature and ocean heat content changes are commonly used metrics to diagnose climate change and estimate properties of the climate system. We show that recent trends, namely the slowing of surface temperature rise at the beginning of the 21st century and the acceleration of heat stored in the deep ocean, have a substantial impact on these estimates. Using the Massachusetts Institute of Technology Earth System Model (MESM), we vary three model parameters that influence the behavior of the climate system: effective climate sensitivity (ECS), the effective ocean diffusivity of heat anomalies by all mixing processes (Kv), and the net anthropogenic aerosol forcing scaling factor. Each model run is compared to observed changes in decadal mean surface temperature anomalies and the trend in global mean ocean heat content change to derive a joint probability distribution function for the model parameters. Marginal distributions for individual parameters are found by integrating over the other two parameters. To investigate how the inclusion of recent temperature changes affects our estimates, we systematically include additional data by choosing periods that end in 1990, 2000, and 2010. We find that estimates of ECS increase in response to rising global surface temperatures when data beyond 1990 are included, but due to the slowdown of surface temperature rise in the early 21st century, estimates when using data up to 2000 are greater than when data up to 2010 are used. We also show that estimates of Kv increase in response to the acceleration of heat stored in the ocean as data beyond 1990 are included. Further, we highlight how including spatial patterns of surface temperature change modifies the estimates. We show that including latitudinal structure in the climate change signal impacts properties with spatial dependence, namely the aerosol forcing pattern, more than properties defined for the global mean, climate sensitivity, and ocean diffusivity.

scholarly journals Milking-related changes of teat temperature caused by various milking machines

2008 ◽  
Vol 53 (No. 4) ◽  
pp. 121-125 ◽  
Author(s):  
J. Vegricht ◽  
A. Machálek ◽  
P. Ambrož ◽  
U. Brehme ◽  
S. Rose
Keyword(s):  
Surface Temperature ◽  
Temperature Rise ◽  
Temperature Fluctuation ◽  
Blood Circulation ◽  
Average Temperature ◽  
Before And After ◽  
Working Quality

The aim of the performed work was to verify the hypothesis that different milking equipments have different influence on the blood circulation in the milk gland during milking. This influence was investigated by measuring the surface temperature of the milk gland using thermography. The influence was monitored of 5 different milking units in total, out of them 2 AMS, on the teat temperature which was scanned and evaluated in the teat tip centre and on the teat base at the same time with the surface temperature of the udder, always at the instant closely preceding the cluster application and then after its removal. It was ascertained that the average temperature of the teat tip after milking was increased in comparison with the temperature before milking practically in all the milking units monitored. At the same time, the average temperature of the teat tip in the milking equipment in parlours increased by about 1.7°C–2.7°C (6.1%–9.0%) as compared to the temperature before milking. At milking in AMS, the temperature rise of the teat tip was smaller and reached only 0.9°C–1.7°C (2.9%–6.0%). At the same time, the temperature of other parts of the milk gland grew commensurately. It was also found that differences exist between different milking units with respect to their influence on the temperature fluctuation of the milk gland. From the monitoring performed up to now and from the results acquired it is possible to apprehend that the monitoring of the teat temperature before and after milking with the help of thermography can become an indicator of the working quality of the milking equipment and its influence on the milk gland. The confirmation of this hypothesis requires, however, further detailed and extensive measuring to be carried out.

Surface Temperature in Oscillating Sliding Interfaces

2004 ◽  
Author(s):  
M. Mansouri ◽  
M. M. Khonsari
Keyword(s):  
Surface Temperature ◽  
Biot Number ◽  
Temperature Rise ◽  
Peclet Number ◽  
Oscillatory Motion ◽  
Péclet Number ◽  
Dimensionless Groups ◽  
Contact Width ◽  
Sliding Interfaces ◽  
Independent Parameters

A model is developed to predict the behavior of two sliding bodies undergoing oscillatory motion. A set of four dimensionless groups is introduced to characterize the transient dimensionless surface temperature rise. They are: the Peclet number Pe, the Biot number Bi, the amplitude of oscillation A, and the Hertzian semi-contact width α. Also considered in the analysis is the effect of the ratio β = A/α of the amplitude to the semi-contact width. The results of a series of simulations, covering a range of these independent parameters, are presented and examples are provided to illuminated the utility of the model.

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