scholarly journals Automation of the stone materials dosing process, controlled by variable frequency drives

2021 ◽  
Vol 24 (2) ◽  
pp. 794
Author(s):  
Guillermo Morales-Romero ◽  
Nicéforo Trinidad-Loli ◽  
Adrián Quispe-Andía ◽  
Beatriz Caycho-Salas ◽  
Shirley Quispe-Guía ◽  
...  
Keyword(s):  
Variable Frequency ◽  
Production Loss ◽  
Annual Average ◽  
Production Time ◽  
Stone Materials ◽  
Variable Frequency Drives ◽  
Before And After ◽  
Stone Material ◽  
A Company

<p>The objective of this article is to determine to what extent the automation of the stone materials dosing process, controlled by sequential drive of frequency variators, contributes to improving the productivity of a company dedicated to the production of asphalt in Peru for which, initially, the characteristics of the procedure that will lead to achieving the automation will be described. The results will then be displayed with respect to the indicators used to compare productivity before and after automation. The automation will be done by means of the logo 230RE controller, which will be connected to three frequency inverters, the programming development will be through the logo soft comford V8 software, for the sequential actuation, timers with connection delay will be used. Applying the automation, it is possible to improve the annual efficiency by an average of 58.30%, this is reflected in the monthly decrease in production time by 13.92%, in turn increasing the amount of stone material produced by an average of 43.77%. Likewise, it is possible to significantly reduce the production loss capacity by an annual average of 93.99%.</p>

scholarly journals Study of the Behavior of Structural Materials Treated with Bioconsolidant

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5369
Author(s):  
Yolanda Spairani ◽  
Arianna Cisternino ◽  
Dora Foti ◽  
Michela Lerna ◽  
Salvador Ivorra
Keyword(s):  
Structural Materials ◽  
Mechanical Tests ◽  
Existing Building ◽  
Experimental Campaign ◽  
Stone Materials ◽  
Before And After ◽  
Optical Photomicrograph ◽  
Stone Material ◽  
Artificial Stone ◽  
Non Destructive

In this article, the effectiveness of the bioconsolidation technique applied to degraded structural materials is illustrated as a new method of consolidation and conservation of the existing building heritage in a less invasive way. Satisfactory results have been obtained by an experimental campaign carried out through non-destructive diagnostic tests, static destructive mechanical tests, and microstructural analyses on a series of natural stone material specimens and artificial stone materials before and after the use of bioconsolidants. The consolidated specimens have been tested after three to four weeks after the application of the M3P nutritional solution on each specimen. The effect on the microstructure of this technique has also been observed using scanning electron microscope and optical photomicrograph, the formation of new calcium carbonate crystals promoting the structural consolidation of the materials under examination was observed in all the specimens analyzed.

Effects of activation frequency and force on low-frequency fatigue in human skeletal muscle

1999 ◽  
Vol 86 (4) ◽  
pp. 1337-1346 ◽  
Author(s):  
Stuart A. Binder-Macleod ◽  
David W. Russ
Keyword(s):  
Healthy Subjects ◽  
Human Skeletal Muscle ◽  
Low Frequency ◽  
Variable Frequency ◽  
Activation Pattern ◽  
Constant Frequency ◽  
Mean Frequency ◽  
Before And After ◽  
Low Frequency Fatigue ◽  
Force Time

No comparison of the amount of low-frequency fatigue (LFF) produced by different activation frequencies exists, although frequencies ranging from 10 to 100 Hz have been used to induce LFF. The quadriceps femoris of 11 healthy subjects were tested in 5 separate sessions. In each session, the force-generating ability of the muscle was tested before and after fatigue and at 2, ∼13, and ∼38 min of recovery. Brief (6-pulse), constant-frequency trains of 9.1, 14.3, 33.3, and 100 Hz and a 6-pulse, variable-frequency train with a mean frequency of 14.3 Hz were delivered at 1 train/s to induce fatigue. Immediately postfatigue, there was a significant effect of fatiguing protocol frequency. Muscles exhibited greater LFF after stimulation with the 9.1-, 14.3-, and variable-frequency trains. These three trains also produced the greatest mean force-time integrals during the fatigue test. At 2, ∼13, and ∼38 min of recovery, however, the LFF produced was independent of the fatiguing protocol frequency. The findings are consistent with theories suggesting two independent mechanisms behind LFF and may help identify the optimal activation pattern when functional electrical stimulation is used.

scholarly journals ANALISIS PERBEDAAN ABNORMAL RETURN DAN VOLUMEPERDAGANGAN SAHAM SEBELUM DAN SESUDAH PILPRES 9 JULI 2014 (STUDI KASUS PERUSAHAAN MILIK BAKRIE GROUP DAN MNC GROUP)

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Suharyati Suharyati ◽  
Sri Hermuningsih
Keyword(s):  
Abnormal Return ◽  
Trading Volume ◽  
Volume Activity ◽  
Average Abnormal Return ◽  
Before And After ◽  
A Company

The purpose of this study to analyze the differences abnormal return and trading volume activity before and after pilpres 9 July 2014, at the company Bakrie Group and MNC Group. The results show: (1) There are no differences in average abnormal return before and after pilpres 9 Juli 2014 on the company Bakrie Group and MNC Group.The absence of a difference is becausereaction IDX to the pilpres 9 July 2014 is instantaneous and not prolonged. (2) There are no differences inaveragetrading volume activitybefore and after pilpres 9 Juli 2014 on the company Bakrie Group, but there are differences in average trading volume activitybefore and after pilpres 9 July 2014 on the companyMNC Group. The discrepancies in the company MNC Group is because investors MNC Group took profit rollicking tacking. While no differences in the company Bakrie Group is because investors Bakrie Group are not bothered by pilpres 9 July 2014. (3) The Company is more affected by pilpres 9 July 2014 is a company owned by MNC Group. Keywords: Abnormal Return,TradingVolumeActivity, Pilpres 9 July 2014.

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