scholarly journals METHODOLOGICAL APPROACHES TO ACCELERATED TESTS OF CRUSHING KNIVES OF GRINDING CATS. COMPARATIVE TESTS OF LOSS OF CUTTING CAPACITY

2021 ◽  
Author(s):  
L. Shustik ◽  
◽  
V. Pogoriliy ◽  
T. Gaidai ◽  
S. Stepchenko ◽  
...  
Keyword(s):  
Impact Load ◽  
Operating Time ◽  
Accelerated Tests ◽  
Plant Debris ◽  
Design Features ◽  
Comparative Tests ◽  
Low Intensity ◽  
Methodological Approaches ◽  
Cyclic Impact ◽  
Cutting Capacity

Abstract. The purpose of the research is to analyze the design features and parameters of grinding knives to compare the intensity of loss of cutting ability of each of the models of knives depending on the load cycles. Methods and materials. Conduct an analytical inspection and instrumental studies of the blades of grinding rollers type KR with different design features. Carry out bench accelerated tests based on the cyclic impact load of the knife fragment due to falling on the simulator of wear cycles and check the residual cutting capacity on the cutting simulator. Justify the coefficient of acceleration of tests as a derivative of hardness and density of the simulator, as well as the ratio of the energy of the fall of the knife fragment on the stand and its rotational motion in the field. Statistical analysis of experimental data was performed by analysis of variance and interpreted by standard computer programs Excel in the form of graphs. Results. Analyzing the proposed method for determining the intensity of loss of cutting ability of the knife when it falls on the simulator of plant debris allowed to rank different models and establish their relative resource. Unhardened models of both 45 and 30MnB5 Steel provide low life and their residual cutting ability is only 15-25% compared to hardened models. Analyzing the research results, the hardened model of a knife made of 45 Steel withstands 4 times more load cycles compared to unhardened models, but is inferior to the hardened model of Steel 30MnB5 (borista), which has the highest resource. Even after 150 load cycles (in terms of the work of a roller with a width of 12.5 m - operating time of more than 1000 ha), it retains more than 55% of the initial cutting ability, which is characterized by low intensity of its loss. Conclusions. According to the tests of the intensity of loss of cutting ability of knives, the most acceptable option for the equipment of roller-shredders is a hardened model made of 30MnB5 Steel (borista), which has the highest resource.

scholarly journals Influence of Cyclic Impact Loading and Axial Stress on Dynamic Mechanical Properties of Burst-Prone Coal

2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Shuang Gong ◽  
Zhen Wang ◽  
Lei Zhou ◽  
Wen Wang
Keyword(s):  
Mechanical Properties ◽  
Impact Loading ◽  
Coal Sample ◽  
Impact Load ◽  
Axial Stress ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Cyclic Impact Loading ◽  
Cyclic Impact ◽  
The Impact

High in-situ stress and frequent dynamic disturbances caused by the mining process in deep coal mines can easily induce dynamic disasters such as coal burst. We conducted laboratory experiments to assess the effects of the axial stress loading and dynamic cyclic impact loading on the dynamic mechanical properties of burst-prone coals by using a modified split Hopkinson pressure bar (SHPB). Comparisons were made using two types of burst-prone and burst-resistant coal samples. The mineral components, organic macerals, and dynamic mechanical features of both burst-prone and burst-resistant coal samples were comparatively analyzed based on the obtained X-ray diffraction (XRD), optical microscope observations, and dynamic compressive stress-strain curves, respectively. The results of the microstructure analysis indicated a larger difference between the minimum and maximum reflectances of vitrinite for burst-prone coal. Compared to the burst-resistant coal samples, the burst-prone coals contained less corpocollinite and fusinite. While applying a high axial static load combined with cyclic impact load, the coal samples showed the characteristics of fatigue damage. The results also demonstrated that preaxial stress affected the burst resistance of coal samples. The greater the preaxial stress was, the less the coal samples could withstand the dynamic cyclic impact load. In comparison to the burst-resistant coal sample, the burst-prone coal sample showed a larger dynamic compressive strength and a lower deformation. They were also more positively capable of the propagation and activation of the coal burst. We believe that the results of the study are conducive to further understanding of the distribution of microcomponents of burst-prone coals. The results are also beneficial for realizing the dynamic mechanical characteristics of burst-prone coals under the impact of cyclic dynamic load.

scholarly journals Bond Durability of Resin Cements to Au-Pd-Ag Alloy under Cyclic Impact Load

2004 ◽  
Vol 23 (2) ◽  
pp. 89-93 ◽  
Author(s):  
Masahiro OHSAWA ◽  
Hiroaki YOKOTA ◽  
Yoshihiko HAYASHI
Keyword(s):  
Impact Load ◽  
Resin Cements ◽  
Cyclic Impact ◽  
Bond Durability

Flexural Analysis on GFRP Composites Subjected to Cyclic Gradual Load and Cyclic Impact

2013 ◽  
Vol 685 ◽  
pp. 35-39 ◽  
Author(s):  
K. Pazhanivel ◽  
N. Ramadoss ◽  
K. Poyyathappan ◽  
P. Anandan ◽  
G.B. Bhaskar
Keyword(s):  
Flexural Strength ◽  
Composite Laminates ◽  
Impact Load ◽  
Flexural Modulus ◽  
Gfrp Composites ◽  
Glass Fiber Reinforced ◽  
Gfrp Composite ◽  
Flexural Analysis ◽  
Cyclic Impact ◽  
Point Bend

Glass fiber reinforced polymeric (GFRP) composite laminates have been prepared by hand layup method. According to ASTM standard, the test specimens have been prepared to carry out the flexural bending tests. The specimens have been subjected to both cyclic impact load and cyclic gradual load with various frequencies prior to the flexural bending analysis. Three point bend method has been adopted to find out the flexural strength and flexural modulus. Flexural strength and modulus have been calculated from the load deflection curve obtained from the tensometer for respective specimens. The flexural bending properties of GFRP composites subjected to cyclic gradual load and cyclic impact have been compared and found that the GFRP composite materials are effective for gradual cyclic load than the cyclic impact load.

scholarly journals Experimental research on cyclic impact load of concrete during curing period

2021 ◽  
Vol 1972 (1) ◽  
pp. 012088
Author(s):  
Chen Chen ◽  
Liu Xiaoyi ◽  
Yu Jianxin ◽  
Liu Pan ◽  
Guo Min
Keyword(s):  
Experimental Research ◽  
Impact Load ◽  
Curing Period ◽  
Cyclic Impact

The parent-offspring microbiome and neurobehavioral development

2019 ◽  
Vol 42 ◽  
Author(s):  
Jeffrey R. Alberts ◽  
Christopher Harshaw ◽  
Gregory E. Demas ◽  
Cara L. Wellman ◽  
Ardythe L. Morrow
Keyword(s):  
Mammalian Species ◽  
Social Emotional ◽  
Behavioral Measures ◽  
Neurobehavioral Development ◽  
Emotional Function ◽  
Neurobehavioral Outcomes ◽  
Methodological Approaches ◽  
And Behavior

Abstract We identify the significance and typical requirements of developmental analyses of the microbiome-gut-brain (MGB) in parents, offspring, and parent-offspring relations, which have particular importance for neurobehavioral outcomes in mammalian species, including humans. We call for a focus on behavioral measures of social-emotional function. Methodological approaches to interpreting relations between the microbiota and behavior are discussed.

Low-Intensity Cognitive Behavioral Therapy

2017 ◽  
Vol 2 (1) ◽  
pp. 31-36
Author(s):  
Pascal Wabnitz ◽  
Michael Schulz ◽  
Michael Löhr ◽  
André Nienaber
Keyword(s):  
Cognitive Behavioral Therapy ◽  
Behavioral Therapy ◽  
Cognitive Behavioral ◽  
Low Intensity

Intraindividual Variability and Stability of Affect and Well-Being

GeroPsych ◽  
2013 ◽  
Vol 26 (3) ◽  
pp. 185-199 ◽  
Author(s):  
Christina Röcke ◽  
Annette Brose
Keyword(s):  
Age Differences ◽  
Well Being ◽  
Subjective Well Being ◽  
Emotional Experiences ◽  
Short Term ◽  
Regulatory Processes ◽  
Functional Implications ◽  
Methodological Approaches ◽  
Underlying Processes

Whereas subjective well-being remains relatively stable across adulthood, emotional experiences show remarkable short-term variability, with younger and older adults differing in both amount and correlates. Repeatedly assessed affect data captures both the dynamics and stability as well as stabilization that may indicate emotion-regulatory processes. The article reviews (1) research approaches to intraindividual affect variability, (2) functional implications of affect variability, and (3) age differences in affect variability. Based on this review, we discuss how the broader literature on emotional aging can be better integrated with theories and concepts of intraindividual affect variability by using appropriate methodological approaches. Finally, we show how a better understanding of affect variability and its underlying processes could contribute to the long-term stabilization of well-being in old age.

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