scholarly journals Establishing the effect of decreased power intensity of self-oscillatory grinding in a tumbling mill when the crushed material content in the intra-chamber fill is reduced

2020 ◽  
Vol 4 (1 (106)) ◽  
pp. 39-48
Author(s):  
Kateryna Deineka ◽  
Yuriy Naumenko
Keyword(s):  
Crushed Material ◽  
Material Content ◽  
Power Intensity ◽  
Tumbling Mill

scholarly journals ESTABLISHING THE ROTATION SPEED VARIATION RANGE LIMITS FOR AUTO-EXCITATION OF SELF-OSCILLATING GRINDING IN A TUMBLING MILL

2020 ◽  
Vol 4 ◽  
pp. 32-35
Author(s):  
Kateryna Deineka ◽  
Yurii Naumenko
Keyword(s):  
Visual Analysis ◽  
Rotation Speed ◽  
Relative Size ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
The Self ◽  
Cement Clinker ◽  
Crushed Material ◽  
Degree Of Filling ◽  
Tumbling Mill

The influence of the structure of a two-fraction polygranular feed of the chamber on the value of the drum rotation speed at auto-excitation of self-excited oscillations with a maximum swing is considered. Such a pulsating mode of movement of the charge is used in the self-oscillating process of grinding in a tumbling mill. The coarse fraction simulated the grinding bodies was steel bullets with a relative size ψdb=0.026. The fine fraction, simulated the particles of the crushed material, was a cement clinker with a relative particle size ψdm=0.00013. Variable factors of experimental studies were: the degree of filling the chamber in the state of rest κbr=0.25; 0.29; 0.33 and the degree of filling the gaps between the particles of the coarse fraction with particles of the fine fraction κmbgr=0.0625; 0.375; 0.6875; 1. The method of visual analysis of transient processes of self-oscillating modes of feed behavior in the cross section of the rotating drum chamber is applied. Measurements of the speed limits of the drum rotation were carried out with auto-excitation of self-oscillations of the filling. The magnitude of the self-oscillation swing was estimated by the increase in the difference between the maximum and minimum values of the filling dilatancy for one period of pulsations. An increase in the upper limit of the speed range ψω2 with a decrease in κbr and κmbgr was established. The growth rate of ψω2 increases at low values of κbr and κmbgr. Some increase in the lower limit of the ψω1 range with a decrease in κbr and κmbgr was revealed. An increase in the range of speeds of rotation was recorded at the maximum range of self-oscillations ψω1–ψω2 with a decrease in the connected interaction of the intra-mill filling. This coherent interaction is due to an increase in κbr and κmbgr. The value of the ψω1–ψω2 range varies from 1.01–1.03 at κbr=0.33 and κmbg=1 to 1.22–1.66 at κbr=0.25 and κmbgr=0.0625. The range gets its maximum value with fine and superfine grinding

Merging Footwear Design and Functionality

2020 ◽  
Vol 20 (4) ◽  
pp. 372-381
Author(s):  
Suzana Kutnjak-Mravlinčić ◽  
Jadranka Akalović ◽  
Sandra Bischof
Keyword(s):  
Science And Technology ◽  
Raw Material ◽  
Quality Level ◽  
Material Content ◽  
Production Concept ◽  
Wear And Tear ◽  
Similar Appearance ◽  
Key Aspects ◽  
Footwear Design

AbstractFunctionality and appearance are key aspects of good footwear. Developments in recent science and technology offer a wider scope of innovations, contributing to diversity and higher complexity of the production concept of footwear. Contemporary industrial footwear market offers a practically limitless number of new design and fashion solutions, often of quite similar appearance, but with significant differences in quality level, both regarding manufacture, raw material content, durability, and in some special functional finishes. The materials for footwear manufacture are functionalized for functional protective purposes, such as antimicrobial, waterproofing, fire resistant, wear and tear resistant, and recently for some therapeutical purposes. Novelties in material functionalization for the materials built in the footwear are most often promoted and presented on tags and labels and are used as advertisement issues, while some functionalities have become a logo for some brands.

TINJAUAN YURIDIS TERHADAP PENGEMBALIAN KEWENANGAN ISTIMEWA MAJELIS PERMUSYAWARATAN RAKYAT MELALUI PERUBAHAN UNDANG-UNDANG DASAR NEGARA REPUBLIK INDONESIA TAHUN 1945

2018 ◽  
Vol 5 (1) ◽  
pp. 142
Author(s):  
Putu Ayu Anastasia Wierdarini
Keyword(s):  
Research Method ◽  
State Institution ◽  
Vice President ◽  
Legal Research ◽  
Conceptual Approach ◽  
Administration System ◽  
Material Content ◽  
The People ◽  
State Administration ◽  
Strategic Position

The amendment of the Undang-Undang Dasar Negara Republik Indonesia Tahun 1945 positioned the Majelis Permusyawaratan Rakyat no longer as the highest state institution and the highest sovereign of the people. This has implications for the authority of the Majelis Permusyawaratan Rakyat to have a strategic position, namely to UUD 1945, to stipulate GBHN, to elect the president and vice president through amendment of its authority to be very limited and weak. This paper examines jurisdictionally how to restore the privileges possessed by the Majelis Permusyawaratan Rakyat through the amendment of the UUD 1945. A normative legal research method with statute approach and conceptual approach is used to analyze this problem.The results of the study indicate that the MPR's repatriation in the main and vital position in the Indonesian state administration system is very important, namely through amendments to the material content of the UUD 1945 which must be implemented on an ongoing basis.

scholarly journals The STAFF-DWP wave instrument on the DSP equatorial spacecraft: description and first results

2005 ◽  
Vol 23 (8) ◽  
pp. 2785-2801 ◽  
Author(s):  
N. Cornilleau-Wehrlin ◽  
H. St. Alleyne ◽  
K. H. Yearby ◽  
B. de la Porte de Vaux ◽  
A. Meyer ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Broad Band ◽  
Temporal Analysis ◽  
Time Interval ◽  
Magnetic Fluctuations ◽  
Quiet Time ◽  
Waveform Data ◽  
Power Intensity ◽  
First Case ◽  
First Results

Abstract. The STAFF-DWP wave instrument on board the equatorial spacecraft (TC1) of the Double Star Project consists of a combination of 2 instruments which are a heritage of the Cluster mission: the Spatio-Temporal Analysis of Field Fluctuations (STAFF) experiment and the Digital Wave-Processing experiment (DWP). On DSP-TC1 STAFF consists of a three-axis search coil magnetometer, used to measure magnetic fluctuations at frequencies up to 4 kHz and a waveform unit, up to 10 Hz, plus snapshots up to 180 Hz. DWP provides several onboard analysis tools: a complex FFT to fully characterise electromagnetic waves in the frequency range 10 Hz-4 kHz, a particle correlator linked to the PEACE electron experiment, and compression of the STAFF waveform data. The complementary Cluster and TC1 orbits, together with the similarity of the instruments, permits new multi-point studies. The first results show the capabilities of the experiment, with examples in the different regions of the magnetosphere-solar wind system that have been encountered by DSP-TC1 at the beginning of its operational phase. An overview of the different kinds of electromagnetic waves observed on the dayside from perigee to apogee is given, including the different whistler mode waves (hiss, chorus, lion roars) and broad-band ULF emissions. The polarisation and propagation characteristics of intense waves in the vicinity of a bow shock crossing are analysed using the dedicated PRASSADCO tool, giving results compatible with previous studies: the broad-band ULF waves consist of a superimposition of different wave modes, whereas the magnetosheath lion roars are right-handed and propagate close to the magnetic field. An example of a combined Cluster DSP-TC1 magnetopause crossing is given. This first case study shows that the ULF wave power intensity is higher at low latitude (DSP) than at high latitude (Cluster). On the nightside in the tail, a first wave event comparison - in a rather quiet time interval - is shown. It opens the doors to future studies, such as event timing during substorms, to possibly determine their onset location.

scholarly journals Effect of Returnable Material in Batch on Hot Tearing Tendency of AlSi9Cu3 Alloy

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1583
Author(s):  
Justyna Kasińska ◽  
Marek Matejka ◽  
Dana Bolibruchová ◽  
Michal Kuriš ◽  
Lukáš Širanec
Keyword(s):  
Raw Materials ◽  
Qualitative Evaluation ◽  
Hot Tearing ◽  
Material Content ◽  
Negative Effect ◽  
Increased Sensitivity ◽  
Materials Used ◽  
Shape Complexity ◽  
Tear Propagation ◽  
Hot Tearing Susceptibility

The main reason for the use of returnable material, or recycled alloys, is a cost reduction while maintaining the final properties of the casting. The casting resulting quality is directly related to the correct ratio of commercial grade alloy and alloy made by remelting the returnable material in the batch. The casting quality is also affected by the purity of the secondary raw materials used, the shape complexity and the use of the casting itself. The presented article focuses on the effect of increasing the returnable material content in the batch on the hot tearing susceptibility of AlSi9Cu3 alloy. Hot tears are a complex phenomenon that combines metallurgical and thermo-mechanical interactions of the cast metal. Hot tearing susceptibility was evaluated on the basis of quantitative (HTS — hot tearing susceptibility index) and qualitative evaluation. The negative effect of returnable material in the batch was already manifested at a 20% content in the batch. The critical proportion of the returnable alloy in the batch can be stated as 50%. The alloy with a 50% returnable material content manifested insufficient results of the HTS index and qualitative evaluation, which means increased sensitivity to tearing. The negative effect of returnable material and the increased sensitivity were also confirmed in the evaluation of the fracture surface and hot tear profile. The microstructure of alloys with 50% and higher proportion of returnable material was characterized by a higher amount of iron phases (mainly Al5FeSi), whose sharp ends acted as critical regions of hot tearing and subsequent hot tear propagation, which had a major impact on the increase in hot tearing susceptibility.

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