scholarly journals On the Influence of Infra-Red Sensor in the Accurate Estimation of Grinding Temperatures

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4134 ◽  
Author(s):  
Lander Urgoiti ◽  
David Barrenetxea ◽  
Jose Sánchez ◽  
Iñigo Pombo ◽  
Jorge Álvarez
Keyword(s):  
Ground Surface ◽  
Added Value ◽  
Accurate Estimation ◽  
Temperature Estimation ◽  
Surface Temperatures ◽  
Measuring Techniques ◽  
Infra Red ◽  
Reduce Measurement Error ◽  
Grinding Conditions ◽  
Estimation System

Workpiece rejection originated by thermal damage is of great concern in high added-value industries, such as automotive or aerospace. Surface temperature control is vital to avoid this kind of damage. Difficulties in empirical measurement of surface temperatures in-process imply the measurement in points other than the ground surface. Indirect estimation of temperatures demands the use of thermal models. Among the numerous temperature measuring techniques, infra-red measurement devices excel for their speed and accurate measurements. With all of this in mind, the current work presents a novel temperature estimation system, capable of accurate measurements below the surface as well as correct interpretation and estimation of temperatures. The estimation system was validated by using a series of tests in different grinding conditions that confirm the hypotheses of the error made when measuring temperatures in the workpiece below the surface in grinding. This method provides a flexible and precise way of estimating surface temperatures in grinding processes and has shown to reduce measurement error by up to 60%.

scholarly journals Estimating snow water equivalent over long mountain transects using snowmobile-mounted ground-penetrating radar

Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. WA183-WA193 ◽  
Author(s):  
W. Steven Holbrook ◽  
Scott N. Miller ◽  
Matthew A. Provart
Keyword(s):  
Ground Penetrating Radar ◽  
Snow Water Equivalent ◽  
Ground Surface ◽  
Snow Accumulation ◽  
Accurate Estimation ◽  
Snow Density ◽  
Snow Stratigraphy ◽  
Flood Estimation ◽  
Snow Water ◽  
Ground Penetrating

The water balance in alpine watersheds is dominated by snowmelt, which provides infiltration, recharges aquifers, controls peak runoff, and is responsible for most of the annual water flow downstream. Accurate estimation of snow water equivalent (SWE) is necessary for runoff and flood estimation, but acquiring enough measurements is challenging due to the variability of snow accumulation, ablation, and redistribution at a range of scales in mountainous terrain. We have developed a method for imaging snow stratigraphy and estimating SWE over large distances from a ground-penetrating radar (GPR) system mounted on a snowmobile. We mounted commercial GPR systems (500 and 800 MHz) to the front of the snowmobile to provide maximum mobility and ensure that measurements were taken on pristine snow. Images showed detailed snow stratigraphy down to the ground surface over snow depths up to at least 8 m, enabling the elucidation of snow accumulation and redistribution processes. We estimated snow density (and thus SWE, assuming no liquid water) by measuring radar velocity of the snowpack through migration focusing analysis. Results from the Medicine Bow Mountains of southeast Wyoming showed that estimates of snow density from GPR ([Formula: see text]) were in good agreement with those from coincident snow cores ([Formula: see text]). Using this method, snow thickness, snow density, and SWE can be measured over large areas solely from rapidly acquired common-offset GPR profiles, without the need for common-midpoint acquisition or snow cores.

Ultra-High Speed Grinding Using a CBN Wheel for a Mirror-Like Surface Finish

2005 ◽  
Vol 291-292 ◽  
pp. 67-72 ◽  
Author(s):  
M. Ota ◽  
T. Nakayama ◽  
K. Takashima ◽  
H. Watanabe
Keyword(s):  
Surface Finish ◽  
High Speed ◽  
High Efficiency ◽  
Ground Surface ◽  
Machining Process ◽  
Grinding Wheel ◽  
Cbn Wheel ◽  
Ultra High Speed ◽  
High Speed Grinding ◽  
Grinding Conditions

There are strong demands for a machining process capable of reducing the surface roughness of sliding parts, such as auto parts and other components, with high efficiency. In this work, we attempted to grind hardened steel to a mirror-like surface finish with high efficiency using an ultra-high speed grinding process. In the present study, we examined the effects of the work speed and the grinding wheel grain size in an effort to optimize the grinding conditions for accomplishing mirror-like surface grinding with high efficiency. The results showed that increasing the work speed, while keeping grinding efficiency constant, was effective in reducing the work affected layer and that the grinding force of a #200 CBN wheel was lower than that of a #80 CBN wheel. Based on these results, a high-efficiency grinding step with optimized grinding conditions was selected that achieved excellent ground surface quality with a mirror-like finish.

scholarly journals Late Weichselian thermal state at the base of the Scandinavian Ice Sheet

2019 ◽  
Author(s):  
Dmitry Y. Demezhko ◽  
Anastasia A. Gornostaeva ◽  
Alexander N. Antipin
Keyword(s):  
Thermal State ◽  
Ice Sheet ◽  
Ground Surface ◽  
Substantial Part ◽  
Temperature Pattern ◽  
Glacial Cycle ◽  
Surface Temperatures ◽  
Scandinavian Ice Sheet ◽  
Late Weichselian ◽  
The Last Glacial

Abstract. Geothermal estimates of the ground surface temperatures for the last glacial cycle in Northern Europe has been analyzed. During the Middle and Late Weichselian (55–12 kyr BP) a substantial part of this area was covered by the Scandinavian Ice Sheet. The analysis of geothermal data has allowed reconstructing limits of the ice sheet extension and its basal thermal state in the Late Weichselian. Ground surface temperatures outside the ice sheet were extremely low (from −8 to −18 °C). Within the ice sheet, there were both thawed and frozen zones. The revealed temperature pattern is generally consistent with the modern one for the ground surface temperatures in Greenland that makes it possible to consider these ice sheets as analogues. The anomalous climatically induced surface heat flux and orbital insolation of the Earth varied consistently outside the glaciation and independently within the limits of the ice sheet.

scholarly journals Ground thermal and geomechanical conditions in a permafrost-affected high-latitude rockslide site (Polvartinden, Northern Norway)

2016 ◽  
Author(s):  
Regula Frauenfelder ◽  
Ketil Isaksen ◽  
Jeannette Nötzli ◽  
Matthew J. Lato
Keyword(s):  
Temperature Regime ◽  
Laser Scanning ◽  
Ground Surface ◽  
Failure Zone ◽  
Climate Data ◽  
Conduction Model ◽  
Near Surface ◽  
Northern Norway ◽  
Surface Temperatures

Abstract. In June 2008, a rockslide detached in the northeast facing slope of Polvartinden, a high-alpine mountain in Signaldalen, Northern Norway. Here, we report on the observed and modelled past and present near-surface temperature regime close to the failure zone, as well as on a subsequent simulation of the subsurface temperature regime, and on initial geomechanical mapping based on laser scanning. The volume of the rockslide was estimated to be approximately 500 000 m3. The depth to the actual failure surface was found to range from 40 m at the back of the failure zone to 0 m at its toe. Visible in-situ ice was observed in the failure zone just after the rockslide. Between September 2009 and August 2013 ground surface temperatures were measured with miniature temperature data loggers at fourteen different localities close to the original failure zone along the northern ridge of Polvartinden, and in the valley floor. The results from these measurements and from a basic three-dimensional heat conduction model suggest that the lower altitudinal limit of permafrost at present is at 600–650 m a.s.l., which corresponds to the upper limit of the failure zone. A coupling of our in-situ data with regional climate data since 1958 suggests a general gradual warming and that a period with highest mean near surface temperatures on record ended four months before the Signaldalen rockslide detached. A comparison with a transient permafrost model run at 10 m depth, representative for areas where snow accumulates, strengthen this findings, which are also in congruence with measurements in nearby permafrost boreholes. It is likely that permafrost in and near the failure zone is presently subject to degradation. This degradation, in combination with the extreme warm year antecedent to the rock failure, is seen to have played an important role in the detaching of the Signaldalen rockslide.

RFThermometer: A Temperature Estimation System with Commercial UHF RFID Tags

2019 ◽  
Author(s):  
Xiangyu Wang ◽  
Jian Zhang ◽  
Zhitao Yu ◽  
Eric Mao ◽  
Senthilkumar C. G. Periaswamy ◽  
...  
Keyword(s):  
Rfid Tags ◽  
Uhf Rfid ◽  
Temperature Estimation ◽  
Estimation System

COMPARISON OF EXPERIMENTALLY MEASURED AND SIMULATED WORKPIECE AND GRINDING WHEEL TOPOGRAPHY USING A NEW DRESSING MODEL

2016 ◽  
Vol 40 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Abdalslam Darafon ◽  
Andrew Warkentin ◽  
Robert Bauer
Keyword(s):  
Surface Finish ◽  
Metal Removal ◽  
Ground Surface ◽  
Cutting Edge ◽  
Edge Density ◽  
Grinding Wheel ◽  
Workpiece Surface ◽  
Wheel Topography ◽  
Grinding Wheel Topography ◽  
Grinding Conditions

This paper presents a new empirical model of the dressing process in grinding which is then incorporated into a 3D metal removal computer simulator to numerically predict the ground surface of a workpiece as well as the dressed surface of the grinding wheel. The proposed model superimposes a ductile cutting dressing model with a grain fracture model to numerically generate the resulting grinding wheel topography and workpiece surface. Grinding experiments were carried out using “fine”, “medium” and “coarse” dressing conditions to validate both the predicted wheel topography as well as the workpiece surface finish. For the grinding conditions used in this research, it was observed that the proposed dressing model is able to accurately predict the resulting workpiece surface finish for all dressing conditions tested. Furthermore, similar trends were observed between the predicted and experimentally-measured grinding wheel topographies when plotting the cutting edge density, average cutting edge width and average cutting edge spacing as a function of depth for all dressing conditions tested.

scholarly journals Holocene paleoenvironmental reconstruction from deep ground temperatures: a comparison with paleoclimate derived from the δ18O record in an ice core from the agassiz Ice Cap, Canadian Arctic Archipelago

1991 ◽  
Vol 37 (126) ◽  
pp. 209-219 ◽  
Author(s):  
Alan E. Taylor
Keyword(s):  
Surface Temperature ◽  
Snow Cover ◽  
Ice Core ◽  
Canadian Arctic ◽  
Ground Surface ◽  
Temperature Profiles ◽  
Canadian Arctic Archipelago ◽  
Ground Surface Temperature ◽  
Ice Cap ◽  
Surface Temperatures

Abstract Changes in ground-surface temperature for the past few hundred years have been derived from deep temperature profiles at three wells in the northeastern Canadian Arctic Archipelago, and compared with the climatic history derived from the oxygen-isotope ratio 18O/16O measured in an ice core from the Agassiz Ice Cap, about 180-260 km to the east. Analysis of the ground-temperature profiles suggests that surface temperatures in the area decreased after the Little Climatic Optimum about 1000 years ago until the Little Ice Age (LIA). About 100 years ago, ground-surface temperatures appear to have increased by 2-5K to reach today’s values, while air temperatures increased by 2-3K, according to the isotope record. Part of the larger ground-surface temperature change may be due to other paleoenvironmental effects, such as an increase in snow cover coincident with the end of the LIA. The δ18O climatic record was successful in predicting the general features of the ground-temperature profiles observed at two of the sites, but not the third. There is contemporary evidence that surface temperatures at the latter site may be substantially modified by other environmental factors such as snow cover.

Optimization of Cutting Edge Truncation Depth for Ultrasonically Assisted Grinding to Finish Mirror Surface

2009 ◽  
Vol 76-78 ◽  
pp. 88-93 ◽  
Author(s):  
Keisuke Hara ◽  
Hiromi Isobe ◽  
Akira Kyusojin
Keyword(s):  
Ground Surface ◽  
Optimization Techniques ◽  
Cutting Edge ◽  
Mirror Surface ◽  
Skilled Workers ◽  
Ultrasonic Oscillation ◽  
Oscillation Effect ◽  
Grinding Conditions ◽  
Grinding Technique ◽  
Face Grinding

High precision mold grinding technique to obtain mirror surface is required which realizes minimization or omission of final polishing by skilled workers. In the previous reports, ultrasonic diamond grinding experiments were carried out to confirm ultrasonic oscillation effect for die steel face grinding. Smooth and glossy surfaces were obtained successfully and little abrasive worn out was found. In the above techniques require cutting edge truncation because the cutting edge shape of a tool affects the ground surface resulting from transcription of cutting edge. This paper describes optimization techniques for the cutting edge truncation of diamond electroplated tools which are used in ultrasonically assisted grinding. Experiments were carried out to confirm truncation effects on the ground surface and grinding force. It was confirmed that roughness was proportional to inverse of thrust force. Minimum roughness in grinding conditions were estimated from the proportional diagrams. The minimum roughness shows limit of roughness on an each grinding condition.

Sign in / Sign up

Export Citation Format

Share Document