scholarly journals Full-Scale Simulation and Validation of Wear for a Mining Rope Shovel Bucket

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 623
Author(s):  
Andreas Svanberg ◽  
Simon Larsson ◽  
Rikard Mäki ◽  
Pär Jonsén
Keyword(s):  
Scale Validation ◽  
Steel Structures ◽  
Material Model ◽  
Full Scale ◽  
Industrial Processes ◽  
Wear Model ◽  
Loading Process ◽  
Arctic Conditions ◽  
Set Up

Failure in industrial processes is often related to wear and can cause significant problems. It is estimated that approximately 1–4% of the gross national product for an industrialized nation is related to abrasive wear. This work aims to numerically predict development of wear for full-scale mining applications in harsh sub-arctic conditions. The purpose is to increase the understanding of wear development in industrial processes and optimize service life and minimize costs related to wear. In the present paper, a granular material model consisting of the discrete element method (DEM) and rigid finite element particles is utilized to study wear in full-scale mining applications where granular materials and steel structures are present. A wear model with the basis in Finnie’s wear model is developed to calculate wear from combined abrasive sliding and impact wear. Novel in situ full-scale experiments are presented for calibration of the wear model. A simulation model of the rope shovel loading process is set up where the bucket filling process is simulated several times, and the wear is calculated with the calibrated wear model. From the full-scale validation, it is shown that the simulated wear is in excellent agreement when compared to the experiments, both regarding wear locations and magnitudes. After validation, the model is utilized to study if wear can be minimized by making small changes to the bucket. One major conclusion from the work is that the presented wear simulator is a suitable tool that can be used for product development and optimization of the loading process.

Full-scale Models for the Study of Repair Techniques on Brick Masonry Surfaces

2021 ◽  
Vol 3 (1) ◽  
pp. 10-15
Author(s):  
Luigia Binda ◽  
Giulia Baronio ◽  
Francesco Cantoni ◽  
Paolo Rocca
Keyword(s):  
Systematic Approach ◽  
Capillary Rise ◽  
Accelerated Aging ◽  
Full Scale ◽  
Moisture Distribution ◽  
Scale Models ◽  
Subsequent Measurement ◽  
Set Up ◽  
Repair Techniques

A systematic approach to the study of durability of wall surface treatments has been set up by the authors since some years. The study, previously based on accelerated aging tests and subsequent measurement of surface deterioration of treated and untreated specimens, has now been extended to full-scale facades. Three small constructions designed by the authors with modular facades made of sandstone and/or soft-mud facing bricks have been built in open field. A continuous content of water in the subsoil can be provided so that the capillary rise of water into the masonry is assured; soluble salts can also be provided from the soil. Some of the facades have been treated with protective materials, some others will be treated after deterioration. Besides collection of data concerning the environment and the moisture and salt movements in the walls, the deterioration of the external surfaces, the influence of mortar joints on moisture distribution and of the position and exposure of the material on the deterioration are being taken into account. Comparison between the in-situ and laboratory results are being carried out in order to adjust the aging tests to the natural environment.

Investigation of nitrite pathways in sugar beet extraction

2014 ◽  
pp. 626-635 ◽  
Author(s):  
Florian Emerstorfer ◽  
Christer Bergwall ◽  
Walter Hein ◽  
Mats Bengtsson ◽  
John P. Jensen
Keyword(s):  
Sugar Beet ◽  
Laboratory Experiments ◽  
Ph Value ◽  
Full Scale ◽  
Chemical Effect ◽  
Spectrophotometric Detection ◽  
Sugar Factory ◽  
Chemical Effects ◽  
Set Up ◽  
Nitrate And Nitrite

The investigations presented in this work were carried out in order to further deepen the knowledge about nitrite pathways in the area of sugar beet extraction. The article consists of two parts with different experimental set-up: the first part focuses on laboratory trials in which the fate of nitrate and nitrite was studied in a so-called mini-fermenter. These trials were carried out using juice from the hot part of the cossette mixer of an Agrana sugar factory in Austria. In the experiments, two common sugar factory disinfectants were used in order to study microbial as well as microbial-chemical effects on nitrite formation and degradation caused by bacteria present in the juice. The trials demonstrated that the direct microbial effect (denitrification) on nitrite degradation is more pronounced than the indirect microbial-chemical effect coming from pH value decrease by these bacteria and subsequent nitrite loss. The second part describes the findings from laboratory experiments and full scale factory trials using a mobile laboratory set-up based on insulated stainless steel containers and spectrophotometric detection of nitrite in various factory juices. The trials were made at two Nordzucker factories located in Finland (factory A) and Sweden (factory B). The inhibiting effect of the two common sugar factory disinfectants on nitrite formation was evaluated in laboratory trials, whereas the full scale trials focused on one disinfectant. Other trials to evaluate potential contamination sources of thermophilic nitrite producing bacteria to the extraction system, reactivation of nitrite producing bacteria in raw juice and the effect of a pH gradient on bacterial nitrite activity in cossette mixer juice are also reported.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

scholarly journals Upscaling THM modeling from small-scale to full-scale in-situ experiments in the Callovo-Oxfordian claystone

2021 ◽  
Vol 144 ◽  
pp. 104582
Author(s):  
D.M. Seyedi ◽  
C. Plúa ◽  
M. Vitel ◽  
G. Armand ◽  
J. Rutqvist ◽  
...  
Keyword(s):  
Full Scale ◽  
Small Scale ◽  
In Situ Experiments

scholarly journals Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2246
Author(s):  
Georgia Charalampous ◽  
Efsevia Fragkou ◽  
Konstantinos A. Kormas ◽  
Alexandre B. De Menezes ◽  
Paraskevi N. Polymenakou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Oil Spills ◽  
Eastern Mediterranean ◽  
Sole Source ◽  
Eastern Mediterranean Sea ◽  
Deep Waters ◽  
Degradation Rates ◽  
Polycyclic Aromatic ◽  
Set Up

The diversity and degradation capacity of hydrocarbon-degrading consortia from surface and deep waters of the Eastern Mediterranean Sea were studied in time-series experiments. Microcosms were set up in ONR7a medium at in situ temperatures of 25 °C and 14 °C for the Surface and Deep consortia, respectively, and crude oil as the sole source of carbon. The Deep consortium was additionally investigated at 25 °C to allow the direct comparison of the degradation rates to the Surface consortium. In total, ~50% of the alkanes and ~15% of the polycyclic aromatic hydrocarbons were degraded in all treatments by Day 24. Approximately ~95% of the total biodegradation by the Deep consortium took place within 6 days regardless of temperature, whereas comparable levels of degradation were reached on Day 12 by the Surface consortium. Both consortia were dominated by well-known hydrocarbon-degrading taxa. Temperature played a significant role in shaping the Deep consortia communities with Pseudomonas and Pseudoalteromonas dominating at 25 °C and Alcanivorax at 14 °C. Overall, the Deep consortium showed a higher efficiency for hydrocarbon degradation within the first week following contamination, which is critical in the case of oil spills, and thus merits further investigation for its exploitation in bioremediation technologies tailored to the Eastern Mediterranean Sea.

scholarly journals Design framework for DEM-supported prototyping of grabs including full-scale validation

2021 ◽  
Vol 96 ◽  
pp. 29-43
Author(s):  
Dingena Schott ◽  
Javad Mohajeri ◽  
Jovana Jovanova ◽  
Stef Lommen ◽  
Wilbert de Kluijver
Keyword(s):  
Scale Validation ◽  
Full Scale ◽  
Design Framework

Advanced Technique for In Situ Raman Spectroscopy Monitoring of the Freezing-Induced Loading Process

Langmuir ◽  
2021 ◽  
Vol 37 (4) ◽  
pp. 1365-1371
Author(s):  
Sergei V. German ◽  
Gleb S. Budylin ◽  
Evgeny A. Shirshin ◽  
Dmitry A. Gorin
Keyword(s):  
Raman Spectroscopy ◽  
In Situ Raman Spectroscopy ◽  
Advanced Technique ◽  
Loading Process ◽  
In Situ Raman

Investigation of planing craft maneuverability using full-scale tests

2021 ◽  
pp. 147509022110303
Author(s):  
Kazem Sadati ◽  
Hamid Zeraatgar ◽  
Aliasghar Moghaddas
Keyword(s):  
Full Scale ◽  
Performance Characteristics ◽  
Forward Speed ◽  
Speed Reduction ◽  
Planing Craft ◽  
Full Scale Tests ◽  
Turning Maneuver

Maneuverability of planing craft is a complicated hydrodynamic subject that needs more studies to comprehend its characteristics. Planing craft drivers follow a common practice for maneuver of the craft that is fundamentally different from ship’s standards. In situ full-scale tests are normally necessary to understand the maneuverability characteristics of planing craft. In this paper, a study has been conducted to illustrate maneuverability characteristics of planing craft by full-scale tests. Accelerating and turning maneuver tests are conducted on two cases at different forward speeds and rudder angles. In each test, dynamic trim, trajectory, speed, roll of the craft are recorded. The tests are performed in planing mode, semi-planing mode, and transition between planing mode to semi-planing mode to study the effects of the craft forward speed and consequently running attitude on the maneuverability. Analysis of the data reveals that the Steady Turning Diameter (STD) of the planing craft may be as large as 40 L, while it rarely goes beyond 5 L for ships. Results also show that a turning maneuver starting at planing mode might end in semi-planing mode. This transition can remarkably improve the performance characteristics of the planing craft’s maneuverability. Therefore, an alternative practice is proposed instead of the classic turning maneuver. In this practice, the craft traveling in the planing mode is transitioned to the semi-planing mode by forward speed reduction first, and then the turning maneuver is executed.

Some observations on rock weathering, Cumberland Peninsula, Baffin Island

1979 ◽  
Vol 16 (5) ◽  
pp. 977-983 ◽  
Author(s):  
Stephen H. Waits
Keyword(s):  
Salt Crystallization ◽  
Rock Weathering ◽  
Baffin Island ◽  
Significant Modification ◽  
Bedrock Weathering ◽  
Arctic Conditions ◽  
Selective Preservation ◽  
Mechanical Weathering ◽  
High Level

A variety of bedrock weathering features—both modern and remnant—including surface grus, polygonal cracks, siliceous glaze, tors, weathering pits, and tafoni typify upland outcrops on the Cumberland Peninsula. Tor ridges are particularly prevalent and at lower elevations they show significant modification and streamlining by flowing ice. On summit areas at elevations above 750 m, however, remnant corestones are preserved in situ, suggesting selective preservation of upland surfaces. Bedrock structure and composition, topographic position, and intensity of process strongly influence tor development. Weathering pits are common on high level, open summit surfaces where weathering occurs in response to both climate and continued removal of derived debris. Pit enlargement through lateral undercutting has been favoured by accumulation of protective bottom residua, mechanical weathering, and the presence of exfoliation crusts. It is postulated that salt crystallization plays a role in outcrop microweathering under present upland arctic conditions.

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