scholarly journals The Effect of Addition of Antioxidant 1,2-dihydro-2,2,4-trimethyl-quinoline on Characteristics of Crepe Rubber Modified Asphalt in Short Term Aging and Long Term Aging Conditions

2020 ◽  
Vol 10 (20) ◽  
pp. 7236
Author(s):  
Bahruddin Ibrahim ◽  
Arya Wiranata ◽  
Alfian Malik

The use of natural rubber to resist bitumen is usually prone to degradation and aging. One method to overcome this problem is the addition of antioxidants. This study aims to determine the effect of the addition of antioxidants 1,2-dihydro-2,2,4-trimethyl-quinoline (TMQ) on natural rubber modified asphalt crepe rubber and its performance in short-term and long-term aging conditions. The modified rubber asphalt mixture’s manufacture begins by melting the crepe rubber at 200 °C before being mixed in asphalt at 165 °C. Addition of antioxidant TMQ during the stirring process of the mixture of asphalt and melted rubber. The crepe rubber content was 8, 10, and 12% w/w, while the TMQ content was 1, 2, and 3% w/w of the total sample weight. The modified asphalt samples’ characterization included penetration, softening point, weight loss after a rolling thin film oven test (RTFOT), penetration after RTFOT, and Marshall test. Review of the performance of asphalt under short-term aging conditions using a dynamic shear rheometer (DSR). Evaluation of asphalt performance under long-term aging conditions using Fourier-transform infrared spectroscopy (FTIR). The results showed that the fact that the best-modified asphalt product was the addition of 10% crepe rubber and 2% TMQ. The best-modified asphalt characteristics have penetration 68.70 dmm, softening point 55.45 °C, weight loss only 0.0579%, penetration after RTFOT 59.60, Marshall stability 1403.96 kg with optimum asphalt content of 5.50%, and rutting factor (G*/Sinδ) 6.91 kPa and 16.1 kPa before and after RTFOT. Overall, the modified crepe rubber asphalt can improve the performance of the asphalt in terms of durability. Simultaneously, the antioxidant TMQ works very well in increasing the resistance of bitumen to aging in the conditions of short-term aging and long-term aging.

2006 ◽  
Vol 31 (03) ◽  
Author(s):  
M Lainscak ◽  
S von Haehling ◽  
A Sandek ◽  
I Keber ◽  
M Kerbev ◽  
...  

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 559-559
Author(s):  
Sara Freed ◽  
Briana Sprague ◽  
Lesley Ross

Abstract Interventions using exercise video games, or exergames, have shown short-term cognitive and physical benefits to older adults, though long-term effects are less promising. Enjoyment of exergames may promote exergame use after the intervention period, though little work has examined older adults’ views of exergames before and after gameplay experience. We invited 20 older adults between 65 and 84 years of age (M=73.30, SD=5.95) to play two Xbox Kinect games, Just Dance and Kinect Sports Rivals, for twenty minutes. In our presentation, we will present qualitative and quantitative findings of this pilot study, including findings that older adults reported that they were not likely to play similar exergames in the future and that they did not find the exergames to be more fun compared to other ways of exercising. We will discuss implications for game design and research relevant to game developers, manufacturers, and researchers. Part of a symposium sponsored by Technology and Aging Interest Group.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaorong Yan ◽  
Huiqing Wang ◽  
Cai Li ◽  
Yuanxiang Lin ◽  
Lin Lin ◽  
...  

Abstract Background To present a surgical technique for the treatment of intradural extramedullary (IDEM) tumors by using endoscopically controlled surgery with open hemilaminectomy technique. Methods In this study, 20 patients with 22 IDEM tumors were enrolled. An endoscopically controlled surgery with open hemilaminectomy was employed to remove the tumors. Data related to clinical symptoms and medical images before and after surgery were collected for perioperative evaluation and follow-up analysis. Results All the tumors in 20 patients were well removed. The clinical symptoms were significantly reduced in all the patients as well. The short-term follow-up data showed that there was no tumor recurrence or spinal deformity. Conclusion The endoscopically controlled surgery with open hemilaminectomy technique provided favorable exposure and satisfactory resection to the IDEM tumors. It may be an effective surgical method for treating IDEM tumors. Larger samples and longer follow-up data are needed to verify its long-term effectiveness.


Fractals ◽  
2013 ◽  
Vol 21 (01) ◽  
pp. 1350001 ◽  
Author(s):  
KAI SHI ◽  
WEN-YONG LI ◽  
CHUN-QIONG LIU ◽  
ZHENG-WEN HUANG

In this work, multifractal methods have been successfully used to characterize the temporal fluctuations of daily Jiuzhai Valley domestic and foreign tourists before and after Wenchuan earthquake in China. We used multifractal detrending moving average method (MF-DMA). It showed that Jiuzhai Valley tourism markets are characterized by long-term memory and multifractal nature in. Moreover, the major sources of multifractality are studied. Based on the concept of sliding window, the time evolutions of the multifractal behavior of domestic and foreign tourists were analyzed and the influence of Wenchuan earthquake on Jiuzhai Valley tourism system dynamics were evaluated quantitatively. The study indicates that the inherent dynamical mechanism of Jiuzhai Valley tourism system has not been fundamentally changed from long views, although Jiuzhai Valley tourism system was seriously affected by the Wenchuan earthquake. Jiuzhai Valley tourism system has the ability to restore to its previous state in the short term.


Circulation ◽  
2016 ◽  
Vol 133 (suppl_1) ◽  
Author(s):  
Nancy R Cook ◽  
Lawrence J Appel ◽  
Paul K Whelton

Introduction: Although weight loss has favorable effects on intermediate outcomes, such as blood pressure and insulin resistance, few studies have examined its effects on long-term outcomes including total mortality. Methods: In the Trials of Hypertension Prevention (TOHP) individuals aged 30-54 years with high normal BP were randomized to a weight loss intervention, to one of several other lifestyle or dietary supplement interventions, or to usual care. All participants from Phase 1 (1987-90) and Phase 2 (1990-5) were followed for mortality through 2013. The association of weight change during any of the interventions with long-term mortality up to 18-24 years after the trial periods was examined among 3828 participants who fell into a high baseline weight stratum, defined as body mass index at least 26 kg/m2 in men and 24 kg/m2 in women. Results and Conclusions: There were 1477 high-weight participants in Phase 1 and 2351 in Phase 2, of whom 21% and 50%, respectively, were assigned to a weight loss intervention. Overall, mean weight change during the trial period was -1.8 lbs (-0.8% of baseline body weight) over 1.5 years in Phase 1 and 1.6 lbs (0.8%) over 3-4 years in Phase 2. A total of 556 (15%) lost > 5%, 1,101 (29%) lost <=5%, 1,567 (41%) gained less than 5%, and 604 (16%) gained > 5% in body weight. Corresponding hazard ratios (HRs) for total mortality were 0.82 (95% confidence interval (CI)=0.57-1.18), 0.94 (95% CI=0.72-1.23), 1.00 (reference), and 1.29 (95% CI=0.92-1.80) (p-trend = 0.046). There was a direct linear relationship with percent change in weight during the trial period and later mortality (HR=1.14 per 5% change, 95% CI=1.02-1.28, p=0.019). This association persisted throughout the course of mortality follow-up (Figure). In these healthy individuals taking part in lifestyle and nutrition supplement trials , short-term weight change was directly associated with mortality about two decades later. These results are consistent with a long-term beneficial effect of presumed intentional weight loss on total mortality.


2020 ◽  
Author(s):  
Xiaorong Yan ◽  
Huiqing Wang ◽  
Cai Li ◽  
Yuanxiang Lin ◽  
Lin Lin ◽  
...  

Abstract Background To present a surgical technique for the treatment of intradural extramedullary (IDEM) tumors by using endoscopically-controlled surgery with open hemi-laminectomy technique. Methods In this study, 20 patients with 22 IDEM tumors were enrolled. An endoscopically-controlled surgery with open hemi-laminectomy was employed to remove the tumors. Data related to clinical symptoms and medical images before and after surgery were collected for perioperative evaluation and follow-up analysis. Results All the tumors in 20 patients were well removed. The clinical symptoms were significantly reduced in all the patients as well. The short term follow-up data showed that there was no tumor recurrence or spinal deformity. Conclusion The endoscopically-controlled surgery with open hemi-laminectomy technique provided favorable exposure and satisfactory resection to the IDEM tumors. It may be an effective surgical method for treating IDEM tumors. Larger samples and longer follow-up data are needed to verify its long-term effectiveness.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0247272
Author(s):  
Claudius Gros ◽  
Roser Valenti ◽  
Lukas Schneider ◽  
Benedikt Gutsche ◽  
Dimitrije Marković

The distinct ways the COVID-19 pandemic has been unfolding in different countries and regions suggest that local societal and governmental structures play an important role not only for the baseline infection rate, but also for short and long-term reactions to the outbreak. We propose to investigate the question of how societies as a whole, and governments in particular, modulate the dynamics of a novel epidemic using a generalization of the SIR model, the reactive SIR (short-term and long-term reaction) model. We posit that containment measures are equivalent to a feedback between the status of the outbreak and the reproduction factor. Short-term reaction to an outbreak corresponds in this framework to the reaction of governments and individuals to daily cases and fatalities. The reaction to the cumulative number of cases or deaths, and not to daily numbers, is captured in contrast by long-term reaction. We present the exact phase space solution of the controlled SIR model and use it to quantify containment policies for a large number of countries in terms of short and long-term control parameters. We find increased contributions of long-term control for countries and regions in which the outbreak was suppressed substantially together with a strong correlation between the strength of societal and governmental policies and the time needed to contain COVID-19 outbreaks. Furthermore, for numerous countries and regions we identified a predictive relation between the number of fatalities within a fixed period before and after the peak of daily fatality counts, which allows to gauge the cumulative medical load of COVID-19 outbreaks that should be expected after the peak. These results suggest that the proposed model is applicable not only for understanding the outbreak dynamics, but also for predicting future cases and fatalities once the effectiveness of outbreak suppression policies is established with sufficient certainty. Finally, we provide a web app (https://itp.uni-frankfurt.de/covid-19/) with tools for visualising the phase space representation of real-world COVID-19 data and for exporting the preprocessed data for further analysis.


2021 ◽  
Vol 22 (24) ◽  
pp. 13609
Author(s):  
Lucas Wauters ◽  
Raúl Y. Tito ◽  
Matthias Ceulemans ◽  
Maarten Lambaerts ◽  
Alison Accarie ◽  
...  

Proton pump inhibitors (PPI) may improve symptoms in functional dyspepsia (FD) through duodenal eosinophil-reducing effects. However, the contribution of the microbiome to FD symptoms and its interaction with PPI remains elusive. Aseptic duodenal brushings and biopsies were performed before and after PPI intake (4 weeks Pantoprazole 40 mg daily, FD-starters and controls) or withdrawal (2 months, FD-stoppers) for 16S-rRNA sequencing. Between- and within-group changes in genera or diversity and associations with symptoms or duodenal factors were analyzed. In total, 30 controls, 28 FD-starters and 19 FD-stoppers were followed. Mucus-associated Porphyromonas was lower in FD-starters vs. controls and correlated with symptoms in FD and duodenal eosinophils in both groups, while Streptococcus correlated with eosinophils in controls. Although clinical and eosinophil-reducing effects of PPI therapy were unrelated to microbiota changes in FD-starters, increased Streptococcus was associated with duodenal PPI effects in controls and remained higher despite withdrawal of long-term PPI therapy in FD-stoppers. Thus, duodenal microbiome analysis demonstrated differential mucus-associated genera, with a potential role of Porphyromonas in FD pathophysiology. While beneficial effects of short-term PPI therapy were not associated with microbial changes in FD-starters, increased Streptococcus and its association with PPIeffects in controls suggest a role for duodenal dysbiosis after long-term PPI therapy.


2021 ◽  
Author(s):  
William Godsoe ◽  
Peter J Bellingham ◽  
Elena Moltchanova

Beta diversity describes the differences in species composition among communities. Changes in beta diversity over time are thought to be due to selection based on species' niche characteristics. For example, theory predicts that selection that favours habitat specialists will increase beta diversity. In practice, ecologists struggle to predict how beta diversity changes. To remedy this problem, we propose a novel solution that formally measures selection's effects on beta diversity. Using the Price equation, we show how change in beta diversity over time can be partitioned into fundamental mechanisms including selection among species, variable selection among communities, drift, and immigration. A key finding of our approach is that a species' short-term impact on beta diversity cannot be predicted using information on its long-term environmental requirements (i.e. its niche). We illustrate how our approach can be used to partition causes of diversity change in a montane tropical forest before and after an intense hurricane. Previous work in this system highlighted the resistance of habitat specialists and the recruitment of light-demanding species but was unable to quantify the importance of these effects on beta diversity. Using our approach, we show that changes in beta diversity were consistent with ecological drift. We use these results to highlight the opportunities presented by a synthesis of beta diversity and formal models of selection.


2020 ◽  
pp. 0000-0000
Author(s):  
Thomas Smith ◽  
G. Ryan Huston ◽  
Richard M. Morton

This study extends the employee stock option literature by examining the impact of accrual management, before and after stock option exercise, on the timing of sales of shares acquired at exercise. We find evidence that accrual management prior to exercise is positively associated with the decision to quickly sell shares after exercise, facilitating a short-term exercise-and-sell strategy. Alternatively, we find that, among executives initially choosing to hold at exercise, tax incentives appear to drive both post-exercise accrual management and the timing of sale transactions. Specifically, our results suggest that executives use income-increasing accruals during the holding period to bolster their stock option gains sand then sell immediately after satisfying the minimum (twelve month) holding period for long-term capital gain treatment. These results provide context for prior research that found evidence of earnings management leading up to option exercise on the expectation of an immediate sale.


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