scholarly journals Basic Research of Improving the Mortar Flow by Thermal Stimulation to Superplasticizer

2019 ◽  
Vol 278 ◽  
pp. 01003
Author(s):  
Mizuki Takigawa ◽  
Fraidoon Rahmanzai ◽  
Rio Kita ◽  
Shigeyuki Date
Keyword(s):  
Thermal Fluctuation ◽  
Basic Research ◽  
Thermal Stimulation ◽  
Polycarboxylic Acid ◽  
Heat Temperature ◽  
Basic Performance ◽  
Long Time ◽  
Stimulation Of

Polycarboxylic acid-based superplasticizers are being used for various fields of concrete work, however little has reported on changing basic performance by thermal fluctuation. In this study, heating superplasticizers itself is hereinafter as referred to as “thermal stimulation”, the effect of thermal stimulation and heat retention of superplasticizer on the fresh mortar, moreover the influence of molecular structural changed of superplasticizer by thermal stimulation were investigated. As the result, it was confirmed that improving fluidity of the mortar flow on this condition the highly heat temperature and heat over a long time by thermal stimulation of superplasticizer. In addition, it turned out that this phenomenon was caused molecular structural changed by thermal stimulation, and the result was revealed that the effect of thermal stimulation varies according to the type of polymer.

scholarly journals Effectiveness of Thermal Stimulation of Superplasticizers on Fresh Properties of Cement Mortar

2021 ◽  
Author(s):  
Mizuki Takigawa ◽  
Hiroshi Nemoto ◽  
Shin-ichiro Hashimoto ◽  
Shigeyuki Date
Keyword(s):  
Cement Mortar ◽  
Plastic Viscosity ◽  
Thermal Stimulation ◽  
Polycarboxylic Acid ◽  
Construction Sites ◽  
Shear Tests ◽  
Polymer Molecules ◽  
Chemical Admixtures ◽  
Environmental Temperatures ◽  
Stimulation Of

AbstractPolycarboxylic acid-based superplasticizers are used in various types of concrete work. Wide variations in environmental temperatures are known to affect how well chemical admixtures perform as superplasticizers, influencing the properties of the concrete. However, little has been reported on changes in performance caused by thermal variations. Previous studies have reported that heating superplasticizers change the polymer structure, improving and sustaining cement particles' dispersibility. Moreover, the improved fluidity from thermal stimulation is not temporary. The effect has been observed to remain for about seven days, with the residual characteristics differing depending on the superplasticizers used. Therefore this study evaluates mortar stiffness when using thermally stimulated superplasticizers and evaluates how the stimulation affects construction performance using measures such as the flow and rheological properties (plastic viscosity) of fresh mortar, vane shear tests, blade viscometer tests, and mortar vibration box tests. Mortar's fluidity was found to improve by about 25% when using thermally stimulated additives, with plastic viscosity dropping by up to 45% and the stress likely to be needed for pumping also being reduced by about 16%. Filling speed was also found to increase by about 26%. Thus, thermal stimulation improves mortar and concrete construction performance, and it may be possible in the future to carry out the construction with fewer workers utilizing this technology’s benefits. The study indicates a need for further investigation of how thermal stimulation affects polymer molecules’ adsorption efficiency with cement to elucidate the mechanism at full scale and propose ways to adopt thermal stimulation at actual construction sites.

Non-Thermal Stimulation of Three-Level Impurities by Phonons

1976 ◽  
Vol 75 (2) ◽  
pp. 507-517 ◽  
Author(s):  
H. Michel ◽  
M. Wagner
Keyword(s):  
Thermal Stimulation ◽  
Stimulation Of

Optical and Thermal Stimulation of Reactions in α-A12O3 Containing V3+, V4+, Co3+, and Co2+

1980 ◽  
Vol 99 (1) ◽  
pp. 377-386 ◽  
Author(s):  
C. J. Delbecq ◽  
S. A. Marshall ◽  
P. H. Yuster
Keyword(s):  
Thermal Stimulation ◽  
Stimulation Of

Convergence of heterotopic nociceptive information onto neurons of caudal medullary reticular formation in monkey (Macaca fascicularis)

1990 ◽  
Vol 63 (5) ◽  
pp. 1118-1127 ◽  
Author(s):  
L. Villanueva ◽  
K. D. Cliffer ◽  
L. S. Sorkin ◽  
D. Le Bars ◽  
W. D. Willis
Keyword(s):  
Electrical Stimulation ◽  
Reticular Formation ◽  
Mechanical Stimulation ◽  
Background Activity ◽  
The Body ◽  
Thermal Stimulation ◽  
Medullary Reticular Formation ◽  
Nociceptive Information ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

1. Recordings were made in anesthetized monkeys from neurons in the medullary reticular formation (MRF) caudal to the obex. Responses of 19 MRF neurons to mechanical, thermal, and/or electrical stimulation were examined. MRF neurons exhibited convergence of nociceptive cutaneous inputs from widespread areas of the body and face. 2. MRF neurons exhibited low levels of background activity. Background activity increased after periods of intense cutaneous mechanical or thermal stimulation. Nearly all MRF neurons tested failed to respond to heterosensory stimuli (flashes, whistle sounds), and none responded to joint movements. 3. MRF neurons were excited by and encoded the intensity of noxious mechanical stimulation. Responses to stimuli on contralateral limbs were greater than those to stimuli on ipsilateral limbs. Responses were greater to stimuli on the forelimbs than to stimuli on the hindlimbs. 4. MRF neurons responded to noxious thermal stimulation (51 degrees C) of widespread areas of the body. Mean responses from stimulation at different locations were generally parallel to those for noxious mechanical stimulation. Responses increased with intensity of noxious thermal stimulation (45-50 degrees C). 5. MRF neurons responded with one or two peaks of activation to percutaneous electrical stimulation applied to the limbs, the face, or the tail. The differences in latency of responses to stimulating two locations along the tail suggested that activity was elicited by activation of peripheral fibers with a mean conduction velocity in the A delta range. Stimulation of the contralateral hindlimb elicited greater responses, with lower thresholds and shorter latencies, than did stimulation of the ipsilateral hindlimb. 6. Electrophysiological properties of monkey MRF neurons resembled those of neurons in the medullary subnucleus reticularis dorsalis (SRD) in the rat. Neurons in the caudal medullary reticular formation could play a role in processing nociceptive information. Convergence of nociceptive cutaneous input from widespread areas of the body suggests that MRF neurons may contribute to autonomic, affective, attentional, and/or sensory-motor processes related to pain.

scholarly journals The assessment of target value of performance indicators of small and medium-sized companies’ financial management with industry and regional environmental features

2019 ◽  
Vol 81 (2) ◽  
pp. 290-300 ◽  
Author(s):  
N. N. Muraveva ◽  
N. S. Talalaeva
Keyword(s):  
Performance Indicators ◽  
Financial Management ◽  
Medium Size ◽  
Small Range ◽  
Economic Agents ◽  
Environmental Features ◽  
Target Values ◽  
Basic Performance ◽  
Long Time ◽  
Standard Values

The efficient financial management in profit organizations are the getting their specific values of basic performance indicators (efficiency criteria), which characterize the solvability, financial capability, profitability of the economic agents. It’s not correct to use standard values estimating the efficiency of small and medium-sized companies’ financial management, being that such enterprises carry on business in the specific industry (there are not the diversification of business) in one specific region, having a small range of activity and sales. This determines the fundamental inequality conditions and objective preconditions their business, being reflected in financial status and results. The research takes into consideration the industry and regional environmental features, using the financial data reporting of profit-making small and medium-size enterprises of the Volgograd Region, which do business in distributive trade, manufacture, building and construction sector. Logics of research based on reference approach to estimate the efficiency of financial management: the values of basic performance indicators of enterprise getting profit a long time in spite of changing in the region’s economic climate, should be taken as the target values corresponding to efficient financial management. Based on research numerical values of industry-specific performance indicators were got. Those indicators are not equal to standard values. The target level of financial indicators serves as a guidemark for small and medium-sized companies to get the efficient financial management and be reaching profitability.

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