Evolution of Synthetic Fluid from Water Extract from Fermented Ground Maize (WEFGM) as an Alternative to Water-Based Cutting Fluids: Performance Test

2018 ◽  
Vol 1150 ◽  
pp. 59-66
Author(s):  
Taofeek Ayotunde Yusuf ◽  
Chibueze Nnorom ◽  
Olusola Femi Olusunmade

The use of agricultural wastes and natural materials in new technologies is a novel subject. Consequently, an attempt has been made to formulate a synthetic fluid using an organic water, Water Extract from Fermented Ground Maize (WEFGM) and compare its performance with water-based sample in turning operation using a mild steel as workpiece. Two samples of synthetic fluids were formulated from each of deionized WEFGM, ordinary WEFGM and deionized water as base-fluids at two composition (5 and 10%vol) levels of selected additives. The results of experimental analysis of heat transfer properties of these synthetic fluids exist, hence the need to ascertain the actual performance output. Temperature-Time Gradient (TTG) which is a rate of temperature drop (heat withdrawn) from the work zone was used as evaluation parameters. The result showed that deionized WEFGM is the most efficient of the entire samples at both compositions with an average TTG of 3.61 and 2.16 °C/min at 10 and 5% additive concentration respectively. At lower additive concentration which is more economically advantageous, the performance rating is deionized WEFGM>>WEFGM>>deionized Water. This implies that WEFGM is more effective than water as a base fluid for synthetic fluid in performance as it has been previously so reported in properties. Meanwhile, T-test statistical analysis (using IBM SPSS 23) shows that there is highly significant difference in TTG at each time of application of individual fluid (p<0.05). However, TTG of one fluid sample is not significantly different from the other (p>0.05) implying that the fluids can all work as coolants and relatively have comparable performance output.

2021 ◽  
pp. 096739112110055
Author(s):  
Gunce Ozan ◽  
Meltem Mert Eren ◽  
Cansu Vatansever ◽  
Ugur Erdemir

Surface sealants are reported to ensure surface smoothness and improve the surface quality of composite restorations. These sealants should also reduce the bacterial adhesion on composite surfaces however, there is not much information regarding their performance on bulk-fill composite materials. The aim of this study was to evaluate the effect of surface sealant application on surface roughness and bacterial adhesion of various restorative materials. Disc-shaped samples were prepared from a compomer, a conventional composite and three bulk-fill composites. Specimens of each group were divided into two groups (n = 9): with/without surface sealant (Biscover LV, [BLV]). Surface roughness values were examined by profilometry and two samples of each group were examined for bacterial adhesion on a confocal laser scanning microscope (CLSM). Bacterial counts were calculated by both broth cultivation and microscopic images. Results were analyzed with one-way ANOVA and Bonferroni/Dunn tests. Following the BLV application, there was a decrease in the surface roughness values of all groups however, only Tetric N-Ceram Bulk and Beautifil-Bulk groups showed significantly smoother surfaces (p < 0.001). There were no significant differences among material groups without BLV application. Evaluating bacterial adhesion after BLV application, conventional composite had the lowest values among all followed by the compomer group. Beautifil-Bulk had significantly the highest bacterial adhesion (p < 0.05), followed by Tetric N-Ceram Bulk group. Without BLV application, there was no significant difference among bacterial adhesion values of groups (p > 0.05). CLSM images showed cell viability in groups. Bulk-fill composites showed higher bacterial adhesion than conventional composite and compomer materials. The surface sealant was found to be highly effective in lowering bacterial adhesion, but not so superior in smoothing the surfaces of restorative materials. So, surface sealants could be used on the restorations of patients with high caries risk.


2002 ◽  
Vol 80 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Mohammed Bajji ◽  
Jean-Marie Kinet ◽  
Stanley Lutts

The effects of salt and osmotic stresses on the germination processes in seeds of the perennial halophyte species Atriplex halimus L. were compared using iso-osmotic concentrations of NaCl and mannitol. The lowest stress intensity delayed germination, while higher doses of NaCl and mannitol reduced final germination percentages. No significant difference occurred between the effects of these solutes on germination percentages or seedling dry weights. At an external osmotic potential of –0.7 MPa, however, the water content of mannitol-treated seedlings was reduced compared to that of seedlings that developed from NaCl-exposed seeds. The K, Mg, and Pi content decreased in seedlings that developed from mannitol-treated seeds while calcium concentration was strongly reduced in those arising from NaCl-treated seeds. Inhibited seeds were able to germinate at levels similar to those of the control after rinsing in deionized water and imbibition in control conditions. Seedlings produced from NaCl pre-treated seeds had a lower Ca and a higher Na content than control seedlings. The effect of salinity on the germination phase of development is mainly due to its osmotic component, and inhibition of germination is reversible. Both salt and osmotic stresses may have an impact on the mobilization of minerals from the seeds to the young seedling, but this effect does not have any consequence on growth processes analysed on a short-term basis.Key words: Atriplex halimus, halophyte, osmotic stress, recovery of seed germination, salinity.


2001 ◽  
Vol 15 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Maria Fernanda Borro BIJELLA ◽  
Maria Francisca Thereza Borro BIJELLA ◽  
Salete Moura Bonifácio da SILVA

This study evaluated, in vitro, marginal microleakage in class II restorations confected with the glass ionomer cement Vitremer and with the composite resins Ariston pHc and P-60. The aims of the study were to assess the effect of thermocycling on those materials and to evaluate two methods utilized in the analysis of dye penetration. Sixty premolars divided in three groups were utilized; the teeth had proximal cavities whose cervical walls were located 1 mm below the cementoenamel junction. Half of the test specimens from each group underwent thermocycling; the other half remained in deionized water, at 37ºC. The specimens were immersed, for 24 hours, in a basic 0.5% fuchsin solution at 37ºC. For the analysis of microleakage, the specimens were sectioned in a mesio-distal direction, and the observation was carried out with the software Imagetools. The results were evaluated through the 2-way ANOVA and through the Tukey’s test. All groups presented marginal microleakage. The smallest values were obtained with Vitremer, followed by those obtained with the composite resins P-60 and Ariston pHc. There was no statistically significant difference caused by thermocycling, and the method of maximum infiltration was the best for detecting the extension of microleakage.


2018 ◽  
Vol 7 (6) ◽  
pp. 509-520 ◽  
Author(s):  
Amitis Vieira Costa e Silva ◽  
Joás Araújo Teixeira ◽  
Cláudia C.B.O. Mota ◽  
Emery Clayton Cabral Correia Lins ◽  
Paulo Correia de Melo Júnior ◽  
...  

AbstractBackgroundNanosilver fluoride (NSF) was developed as an alternative in the prevention of dental caries.PurposeThe aim of this study was to test the remineralizing action of NSF on incipient enamel caries and its antimicrobial action on the acid production and adhesion of Streptococcus mutans.MethodsDeciduous enamel fragments were treated with sodium fluoride (NaF), NSF and deionized water. Microhardness, fluorescence spectroscopy and optical coherence tomography imaging were performed on each specimen before chemical caries induction, after caries induction and after 14 days of pH cycling. The treated enamel fragments were also placed into test tubes containing bacterial suspension and saliva. The pH readings and quantification of the adhered microorganisms to the dental enamel were determined. Analysis of variance, Kruskal-Wallis, Mann-Whitney, Tukey and mixed linear regression model were applied.ResultsNSF and NaF were effective in enamel remineralization, with a statistically significant difference (p<0.001) to deionized water, and they had no statistically significant difference between themselves (p>0.005). NSF had greater effectiveness compared to NaF in preventing decreases of pH and adhesion of S. mutans to the enamel surface, with statistically significant (p<0.001) differences.ConclusionNSF may be more effective than conventional fluorides in treating incipient caries lesions due to its remineralization and antibacterial actions.


2018 ◽  
Vol 4 (1) ◽  
pp. e000389 ◽  
Author(s):  
Bruno A P Alvarenga ◽  
Ricardo Fujikawa ◽  
Filipa João ◽  
Jerusa P R Lara ◽  
António P Veloso

Background and aimMusculoskeletal disorders in athletes, including spinal biomechanical dysfunctions, are believed to negatively influence symmetry. Spinal manipulative therapy (SMT) is recognised as a safe and effective treatment for musculoskeletal disorders, but there is little evidence about whether it can be beneficial in symmetry. Therefore, this study aimed to measure the effects of lumbar SMT in symmetry.MethodsForty asymptomatic athletes participated in the study. The randomisation procedure was performed according to the following group allocation: group 1 (SMT) and group 2 (SHAM). Each participant completed a physical activity questionnaire, and also underwent clinical and physical evaluation for inclusion according to eligibility criteria. Statistical significance (P<0.05) between groups and types of therapy were calculated by physical performance tests symmetry (static position, squat and counter movement jump (CMJ), pre- and post-SMT and SHAM. There were 14 trials of three symmetry tests for each participant, for a total of 560 trials.ResultsLumbar SMT produced immediate effects in symmetry in the static position; however, the same effects were not found in squat and CMJ on symmetry 1. Therefore, our results showed a significant difference in pre- (mean 16.3%) and post-lumbar SMT (mean 3.7%) in static symmetry. However, symmetry 2 showed no statistical significant differences for any of the tests and intervention groups. No statistically significant effects in symmetry pre- to post-SHAM were found in any of the tests.ConclusionsStatistically significant differences were found in lumbar SMT, but only for static symmetry. These findings suggest that SMT was effective in producing immediate effects in symmetry in the static position, but none in dynamic tests. Future studies could address our study's limitations.Clinical trials register numberNCT03361592.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Caibing Liu ◽  
Fang Li ◽  
Guohao Chen ◽  
Xin Huang

With the integration of new technologies such as smart technologies and cloud computing in the industrial Internet of Things, the complexity of industrial IoT applications is increasing. Real-time performance and determinism are becoming serious challenges for system implementation in these Internet of Things systems, especially in critical security areas. This paper provides a framework for a software-defined bus-based intelligent robot system and designs scheduling algorithms to make TTEthernet play the role of scheduling in the framework. Through the framework, the non-real-time and uncertainties problem of distributed robotic systems can be solved. Moreover, a fragment strategy was proposed to solve the problem of large delay caused by Rate-Constrained traffic. Experimental results indicate that the improved scheme based on fragmentation strategy proposed in this paper can improve the real-time performance of RC traffic to a certain extent. Besides, this paper made a performance test and comparison experiments of the improved scheme in the simulation software to verify the feasibility of the improved scheme. The result showed that the delay of Rate-Constrained traffic was reduced and the utilization rate of network was improved.


2011 ◽  
Vol 26 (S2) ◽  
pp. 1560-1560
Author(s):  
S. Miyata ◽  
A. Noda ◽  
M. Ito ◽  
K. Iwamoto ◽  
N. Ozaki

IntroductionSleep restriction has adverse effects on performance and neurobehavioral function. However, the mechanism of impaired performance and neurobehavioral function has not been studied yet.ObjectivesWe examined the effect of insufficient sleep on cerebral blood flow and cognitive function in 8 healthy adults (mean age 22.4 years).MethodsAll participants were in bed for 8 h (sufficient sleep), and for < 4 h (insufficient sleep). The oxyhemoglobin (oxyHb) level by a word fluency task was measured with a near-infrared spectroscopy recorder on the morning following sufficient and insufficient sleep periods. Wisconsin card sorting test (WCST), continuous performance test (CPT) and N-back test were evaluated on the same days.ResultsThe peak oxyHb level was significantly lower in the left and right frontal lobes after insufficient sleep than after sufficient sleep (left: 0.25 ± 0.10 vs. 0.70 ± 0.29 mmol, P < 0.05; right: 0.23 ± 0.13 vs. 0.73 ± 0.22 mmol, P < 0.05). There was no significant difference in the number of words generated during the word fluency task between sufficient and insufficient sleep states. The percentage of correct responses on CPT after insufficient sleep was significantly lower than that after sufficient sleep (86.6 ± 10.2 vs. 96.0 ± 4.9%, P < 0.05). The reaction time of WCST was significantly longer after insufficient sleep than after sufficient sleep (76.6 ± 13.4 vs. 70.6 ± 16.2 sec, P < 0.05).ConclusionsOne night sleep restriction decreased the concentration changes of oxyHb in brain tissue, leading to impaired cognitive function.


1969 ◽  
Vol 24 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Kragg P. Kysor ◽  
James J. Hart

Equations were fitted to learning data obtained on the Number Facility (NF) subtest of the Repetitive Psychometric Measures. Ss were divided into three groups to increase the correlation between their individual scores and the resulting equations. The equations were derived from the pooled scores of two samples. The theoretical performance of Ss based on a logarthmic function was then compared with the actual performance of a third sample. The amount of variability accounted for by the equations ranged from 53 to 86%.


Author(s):  
Didik Sukriono ◽  
Sudirman Sudirman

This article analyzes the development of virtual learning capabilities through massive open online courses (MOOC) on Pancasila Education. The Pancasila Education course has only been delivered in traditionally managed classes by relying on face-to-face meetings. Therefore there needs to be a new approach in Pancasila education to deal with 21st century learning. This research was designed as a research and development education (R&amp;D). Starts with developingthe MOOC Pancasila education platform and conducting tests on students.  The research instrument used in this study was the learning outcomes (scores) of students taking Pancasila education courses. The data analysis used is the independent sample t test, which is a statistical test to find out the differences between two samples that are not interconnected. The result of the development is known that virtual learning through the MOOC platform can increasing students’ score. That are known from the average of virtual class score than traditional classes, but the level of equality is lower values than virtual classes. This average that not all students in one membership can receive virtual classes equally. The traditional and virtual classes of the Pancasila education has a significant difference


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 67-73
Author(s):  
Ahmet Akay ◽  
Özkan Adıgüzel ◽  
Seda Erkan Akay ◽  
Sadullah Kaya

Aim: The purpose of this in vitro study is to compare the cyclic fatigue resistance of Reciproc Nickel-Titanium (Ni-Ti) rotary files while operating root canals using in three different reciprocal angles. Methodology: Forty-five pieces of Reciproc R25 canal files were tested using artificial canals with a 60° angle of curvature, 5 mm curvature radius, and 1.5 mm diameter carved into a stainless steel block. The Ni-Ti files were checked with a stereomicroscope and then randomly separated into 3 groups. Group 1 consisted of reciprocal angles CCW 150°–CW 30°, Group 2 consisted of CCW 180°–CW 60°, and Group 3 consisted of CCW 210°–CW 90°. The duration of the cyclic fatigue being measured, elapsed time until a file fractured was determined with a chronometer. The lengths of the fractured pieces were measured with a digital caliper. After the cyclic fatigue test, two samples from each group were examined with a Scanning Electron Microscope (SEM) to determine the signs of cyclic fatigue. Results: One-way analysis of variance (ANOVA) was applied to the normally distributed groups (p<0,05). Since there was a significant statistical difference of file’s cyclic fatigue resistance (p=0,001) between the groups, Tukey’s honestly significant difference (HSD) post-hoc pairwise comparison test were used for determine to between which groups. While there were statistically significant differences between Group 1 and Group 2 (p=0,001), and between Group 1 and Group 3 (p=0,001), there was no significant difference between Group 2 and Group 3 (p=0,376). Group 1 displayed the highest resistance to cyclic fatigue. There were no statistically significant differences between the lengths of the fractured files within the three groups according to the one-way analysis of variance (p=0,847). Conclusion: In our study, it was observed that the reciprocal angles of CCW 150°–CW 30°, which were also suggested by the file manufacturer firms, had the highest fracture resistance against cyclic fatigue.   How to cite this article: Akay A, Adıgüzel Ö, Erkan Akay S, Kaya S. Comparison of cyclic fatigue of a reciprocating file system at different angles of rotation. Int Dent Res 2021;11(Suppl.1):67-72. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.11   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.  


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